1946 military human subject research on the effects of wind on humans
Human subject research is systematic, scientific investigation
that can be either interventional (a "trial") or observational (no
"test article") and involves human beings as research subjects, commonly known as test subjects. Human subject research can be either medical (clinical) research or non-medical (e.g., social science) research.
Systematic investigation incorporates both the collection and analysis
of data in order to answer a specific question. Medical human subject
research often involves analysis of biological specimens, epidemiological and behavioral studies and medical chart review studies. (A specific, and especially heavily regulated, type of medical human subject research is the "clinical trial",
in which drugs, vaccines and medical devices are evaluated.) On the
other hand, human subject research in the social sciences often involves
surveys which consist of questions to a particular group of people. Survey methodology includes questionnaires, interviews, and focus groups.
Human subject research is used in various fields, including research into advanced biology, clinical medicine, nursing, psychology, sociology, political science, and anthropology.
As research has become formalized, the academic community has developed
formal definitions of "human subject research", largely in response to abuses of human subjects.
Human subjects
The United States Department of Health and Human Services
(HHS) defines a human research subject as a living individual about
whom a research investigator (whether a professional or a student)
obtains data through 1) intervention or interaction with the individual,
or 2) identifiable private information (32 CFR219.102). (Lim, 1990)
Intervention – physical procedures by which data is
gathered and the manipulation of the subject and/or their environment
for research purposes.
Interaction – communication or interpersonal contact between investigator and subject.
Private Information – information about behavior that occurs
in a context in which an individual can reasonably expect that no
observation or recording is taking place, and information which has been
provided for specific purposes by an individual and which the
individual can reasonably expect will not be made public.
Identifiable information – specific information that can be used to identify an individual.
Human subject rights
In 2010, the National Institute of Justice in the United States published recommended rights of human subjects:
The right to end participation in research at any time
Right to safeguard integrity
Protection from physical, mental and emotional harm
Access to information regarding research
Protection of privacy and well-being
Ethical guidelines
In general, it can be said that experimental infections in humans are
tightly linked to a history of scandals in medical research, with
scandals being followed by stricter regulatory rules.
Ethical guidelines that govern the use of human subjects in research
are a fairly new construct. In 1906 some regulations were put in place
in the United States to protect subjects from abuses. After the passage
of the Pure Food and Drug Act in 1906, regulatory bodies such as the Food and Drug Administration (FDA) and institutional review boards
(IRBs) were gradually introduced. The policies that these institutions
implemented served to minimize harm to the participant's mental and/or
physical well being.
The Common Rule
The Common Rule, first published in 1991, also known as the Federal Policy for the Protection of Human Subjects, is dictated by the Office of Human Research Protections under the United States Department of Health and Human Services and serves as a set of guidelines for institutional review boards (IRBs), obtaining informed consent, and Assurances of Compliance for human subject participants in research studies. On January 19, 2017, a final rule was added to the Federal Register with an official effective date of July 19, 2018.
Nuremberg Code
In 1947, German physicians who conducted deadly or debilitating
experiments on concentration camp prisoners were prosecuted as war
criminals in the Nuremberg Trials.
That same year, the Allies established the Nuremberg Code, the first
international document to support the concept that "the voluntary
consent of the human subject is absolutely essential". Individual
consent was emphasized in the Nuremberg Code in order to prevent
prisoners of war, patients, prisoners, and soldiers from being coerced
into becoming human subjects. In addition, it was emphasized in order to
inform participants of the risk-benefit outcomes of experiments.
Declaration of Helsinki
The Declaration of Helsinki was established in 1964 to regulate
international research involving human subjects. Established by the World Medical Association, the declaration recommended guidelines for medical doctors conducting biomedical research
that involves human subjects. Some of these guidelines included the
principles that "research protocols should be reviewed by an independent
committee prior to initiation" and that "research with humans should be
based on results from laboratory animals and experimentation".
The Declaration of Helsinki is widely regarded as the cornerstone document on human research ethics.
The Belmont Report
The Belmont Report was created by the National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research
to describe the ethical behaviors that involve researching human
subjects. It is most heavily used by the current United States system
for protecting human subjects in research trials.
By looking primarily at biomedical and behavioral research that involve
human subjects, the report was generated to promise that ethical
standards are followed during research of human subjects.
There are three standards that serve as the baseline for the report and
how human subjects are to be researched. The three guidelines are beneficence (ethics), justice and respect for persons. Beneficence (ethics)
is described as protecting the well-being of the persons and respecting
their decisions by being ethical and protecting the subjects from harm.
The two rules of beneficence are maximizing the benefits of research
and minimizing any possible risks.
It is the job of the researcher to inform the persons of the benefits
as well as the risks of human subject research. Justice is important
because it causes the researchers to be fair in their research findings
and share what they have found, whether the information is good or bad. The selection process of the subject is supposed to be fair and not separate due to race, sexual orientation or ethnic group.
Lastly, respect for persons explains that at any point a person who is
involved in a study can decide whether they want to participate, not to
participate or withdraw themselves from the study altogether. Two rules
of respect for persons involve the person being autonomous and persons
with diminished autonomy and entitled to protection.
The sole purpose of these guidelines is to ensure autonomy and to
protect against those with a lesser chance to remain autonomous because
of something out of their control.
Ethical concerns
As
science and medicine evolve, the field of bioethics struggles to keep
up with updating guidelines and rules to follow. There has been an
interest in revisiting the ethics behind human subject trials. Members
of the health field have commented that it may be useful to have ethics
classes available to students studying to be health care professionals
as well as have more discussions surrounding the issues and importance
of informed consent.
There have also been a bigger push to protect participants in clinical
trials. Rules and regulations of clinical trials can vary by country.
Suggestions to remedy this include installing a committee to keep
better track of this information and ensure that everything is properly
documented.
Research coordinators and physicians involved in clinical studies have
their own concerns, particularly that an implementation of ethics rules
could potentially disrupt the logistics of preparing a research study,
specifically when it comes to enrolling patients.
Another concern that research teams may have is that even if the rules
are ethically sound, they may not be logical or helpful for conducting
their studies.
Of note currently in the research field is the manner in which
researchers direct their conversations with potential human subjects for
a research study.
Research in rural communities
Recently
there has been a shift from conducting research studies at research
institution facilities or academic centers to rural communities. There
is concern surrounding the topics addressed during the discussions with
this specific demographic of participants, particularly having to do
with funding, overall efficacy of the treatment being studied, and if
conducting such studies is done to the highest ethical standard.
Ann Cook and Freeman Hoas from the University of Montana's Department of Psychology conducted a study
to gain more understanding about what influences potential candidates
to consent to participation in any given clinical trial. They published
their findings in February 2015. Cook and Hoas asked for the
perspectives of the researchers and whether they would consent to being a
subject in a clinical trial. To assess the shift to rural communities,
they surveyed 34 physicians or researchers and 46 research coordinators
from states that have “large rural populations and have historically
demonstrated limited participation in clinical research.”
Proper consent forms were provided and signed at the start of the
study. Of the physicians and research coordinators that participated in
this study, 90% were from hospital centers or worked in a
hospital-clinic setting. Of all the participants, only 66% of research
coordinators and 53% of physicians received training in research
methods, while 59% of the coordinators received any ethics training.
Only 17% of the physicians had ethics research training prior to this
study.
Hoas and Cook categorized their findings into the following main topics:
source of funding
morally nagging and challenging issues
willingness to join a research study
The role of funding
Cook
and Hoas found that funding played a significant role in participant
selection. One of Hoas's and Cook's participants commented that "in his
practice, the income from conducting pharmaceutical trials sometimes
[is] used to offset the losses of conducting scientifically interesting
but poorly funded federal studies,"
and most other participants administered trials because "reimbursements
generated from such trials made it possible to maintain a financially
viable, as well as profitable, practice."
Cook and Hoas found that most of the physicians and coordinators could
not explain directly if they actually told their patients or subjects
about any financial compensation they received. Respondents worry that
discussing funding or compensation would affect enrollment, effectively
swaying participants from joining a research study. In most respondents’
experience, most patients do not even ask for that information, so they
assume that they do not have to discuss it with them and not jeopardize
enrollment. When asked if information about funding or compensation
would be important to provide to patients, one physician replied
“...certainly it may influence or bring up in their mind questions
whether or not, you know, we want them to participate because we’re
gonna get paid for this, you know, budget dollar amount. But, you know,
when you talk about full disclosure, is that something that we should be
doing? That’s an interesting question.”
Morally nagging or challenging issues
Respondents
more often pointed out practical or logistical issues with the overall
process rather than ethical issues. There was a general consensus that
the whole practice of conducting research studies was more focused on
the business aspects like funding and enrolling participants in the
study in time. A physician commented that “[industry] relationships are
very important because of cash flow.”
Typical ethical issues that arise in this type of research trials
include participant enrollment, the question of coercion if a physician
refers their own patients, and any misunderstandings regarding
treatment benefits. Patients are more likely to enroll in a trial if
their primary care physician or a provider that they trust recommends
the study. Most respondents seem to
agree that patients consent to participate because they believe that
through this study, they would be receiving “more attention than my
regular patients” and that “there are an awful lot of additional opportunities for interaction.”
One respondent commented “...the way that we’re required to actually
recruit patients, which is to have their providers be the point of
contact, some ways is--I mean, I don’t want to use the word ‘coercion’,
but it's kind of leaning in that direction because basically here's this
person that they entrust themselves to, who they're very dependent on
for, you know, getting their healthcare.”
There was a large amount of respondents who thought that research
participants did not read or understand the documents provided for
informed consent. However, those respondents did not believe that was an ethical or moral concern.
Willingness to join a research study
Most
of the coordinators and researchers showed some hesitation when they
were asked if they would enroll as a subject in a clinical trial, not
necessarily their own, but any study. When asked to elaborate on their
hesitation, many said that they would be “concerned about the
motivations behind the study, its purpose, its funding, as well as
expectations of what participation might entail.”
Ultimately, only 24% of the respondents said they would be willing to
participate with a majority of them stating they would need full
transparency and an indication that there would be some personal benefit
in order for them to even consider participating. Some had a list of
criteria that had to be met. Eleven percent indicated that they would
not at all be willing to enroll in a research study. One respondent
commented “If it involved taking a medication, no. Never. I would be in a
clinical trial if there was something, like...track [your]
mammogram…[something] I am already subjecting myself to.”
Cook and Hoas stated that these answers were “particularly puzzling”
because “these respondents still reported that their
patient/participants received ‘optimal care’ ” from clinical trials.
Clinical trials
Clinical trials are experiments done in clinical research. Such prospective
biomedical or behavioral research studies on human participants are
designed to answer specific questions about biomedical or behavioral
interventions, including new treatments (such as novel vaccines, drugs, dietary choices, dietary supplements, and medical devices) and known interventions that warrant further study and comparison. Clinical trials generate data on safety and efficacy. They are conducted only after they have received health authority/ethics committee
approval in the country where approval of the therapy is sought. These
authorities are responsible for vetting the risk/benefit ratio of the
trial - their approval does not mean that the therapy is 'safe' or
effective, only that the trial may be conducted.
Depending on product type and development stage, investigators initially enroll volunteers and/or patients into small pilot studies,
and subsequently conduct progressively larger scale comparative
studies. Clinical trials can vary in size and cost, and they can involve
a single research center or multiple centers, in one country or in multiple countries. Clinical study design aims to ensure the scientific validity and reproducibility of the results.
Trials can be quite costly, depending on a number of factors. The sponsor may be a governmental organization or a pharmaceutical, biotechnology or medical device company. Certain functions necessary to the trial, such as monitoring and lab work, may be managed by an outsourced partner, such as a contract research organization
or a central laboratory. For example, a clinical drug trial case at the
University of Minnesota that was under investigation in 2015 for the Death of Dan Markingson was funded by AstraZeneca, a pharmaceutical company headquartered in the United Kingdom.
Human subjects in psychology and sociology
Stanford prison experiment
A study conducted by Philip Zimbardo in 1971 examined the effect of social roles on college students at Stanford University.
Twenty-four male students were assigned to a random role of a prisoner
or guard to simulate a mock prison in one of Stanford's basements. After
only six days, the abusive behavior of the guards and the psychological
suffering of prisoners proved significant enough to halt the
two-week-long experiment.
The goal of the experiment was to determine whether dispositional
factors (the behavior of guards and prisoners) or positional factors
(the social environment of prisons) are the major cause of conflict
within such facilities. The results of this experiment showed that
people will readily conform to the specific social roles they are
supposed to play. The prison environment played a part in making the
guards behavior more brutal, due to the fact that none of the
participants showed this type of behavior beforehand. Most of the guards
had a hard time believing they had been acting in such a way. The
evidence concludes this to be positional behavior, meaning the behavior
was due to the hostile environment of the prison.
Milgram experiment
In 1961, Yale University psychologist Stanley Milgram
led a series of experiments to determine to what extent an individual
would obey instructions given by an experimenter. Placed in a room with
the experimenter, subjects played the role of a "teacher" to a "learner"
situated in a separate room. The subjects were instructed to administer
an electric shock to the learner when the learner answered incorrectly
to a set of questions. The intensity of this electric shock was to be
increased for every incorrect answer. The learner was a confederate
(i.e. actor), and the shocks were faked, but the subjects were led to
believe otherwise. Both prerecorded sounds of electric shocks and the
confederate's pleas for the punishment to stop were audible to the
"teacher" throughout the experiment. When the subject raised questions
or paused, the experimenter insisted that the experiment should
continue. Despite widespread speculation that most participants would
not continue to "shock" the learner, 65 percent of participants in
Milgram's initial trial complied until the end of the experiment,
continuing to administer shocks to the confederate with purported
intensities of up to "450 volts".
Although many participants questioned the experimenter and displayed
various signs of discomfort, when the experiment was repeated, 65
percent of subjects were willing to obey instructions to administer the
shocks through the final one.
Asch conformity experiments
Psychologist Solomon Asch's
classic conformity experiment in 1951 involved one subject participant
and multiple confederates; they were asked to provide answers to a
variety of different low-difficulty questions.
In every scenario, the multiple confederates gave their answers in
turn, and the subject participant subject was allowed to answer last. In
a control group
of participants, the percentage of error was less than one percent.
However, when the confederates unanimously chose an incorrect answer, 75
percent of the subject participants agreed with the majority at least
once. The study has been regarded as significant evidence for the power
of social influence and conformity.
Robber's Cave study
A classic advocate of Realistic conflict theory, Muzafer Sherif's Robber's Cave experiment shed light on how group competition can foster hostility and prejudice.
In the 1961 study, two groups of ten boys each who were not "naturally"
hostile were grouped together without knowledge of one another in Robber's Cave State Park, Oklahoma.
The twelve-year-old boys bonded with their own groups for a week before
the groups were set in competition with each other in games such as
tug-of-war and football. When competing, the groups resorted to
name-calling and other displays of resentment, such as burning the other
group's team flag. The hostility continued and worsened until the end
of the three-week study, when the groups were forced to work together to
solve problems.
Bystander effect
The bystander effect is demonstrated in a series of famous experiments by Bibb Latane and John Darley.
In each of these experiments, participants were confronted with a type
of emergency, such as the witnessing of a seizure or smoke entering
through air vents. A common phenomenon was observed that as the number
of witnesses or "bystanders" increases, so does the time it takes for
individuals to respond to the emergency. This effect has been shown to
promote the diffusion of responsibility by concluding that, when surrounded by others, the individual expects someone else to take action.
Cognitive dissonance
Human subjects have been commonly used in experiments testing the theory of cognitive dissonance after the landmark study by Leon Festinger and Merrill Carlsmith.
In 1959, Festinger and Carlsmith devised a situation in which
participants would undergo excessively tedious and monotonous tasks.
After the completion of these tasks, the subjects were instructed to
help the experiment continue in exchange for a variable amount of money.
All the subjects had to do was simply inform the next "student" waiting
outside the testing area (who was secretly a confederate) that the
tasks involved in the experiment were interesting and enjoyable. It was
expected that the participants wouldn't fully agree with the information
they were imparting to the student, and after complying, half of the
participants were awarded $1, and the others were awarded $20. A
subsequent survey showed that, by a large margin, those who received
less money for essentially "lying" to the student came to believe that
the tasks were far more enjoyable than their highly paid counterparts.
Vehicle safety
In the automotive industry, research has shown that civilian volunteers decided to participate in vehicle safety research to help automobile
designers improve upon safety restraints for vehicles. This research
allows designers to gather more data on the tolerance of the human body
in the event of an automobile accident, to better improve safety
features in automobiles. Some of the tests conducted ranged from sled
runs evaluating head–neck injuries, airbag tests, and tests involving military vehicles
and their restraint systems. From thousands of tests involving human
subjects, results indicate no serious injuries were persistent. This is
largely due to the preparation efforts of researchers to ensure all
ethical guidelines are followed and to ensure the safety and well-being
of their subjects. Although this research provides positive
contributions, there are some drawbacks and resistance to human subject
research for crash testing due to the liability of injury and the lack
of facilities that have appropriate machinery to perform such
experiments. Research with live persons provides additional data which
might be unobtainable when testing with cadavers or crash test dummies.
Social media
The increased use of social media as a data source for researchers has led to new uncertainties regarding the definition of human subject research. Privacy, confidentiality, and informed consent
are key concerns, yet it is unclear when social media users qualify as
human subjects. Moreno et al. conclude that if access to the social
media content is public, information is identifiable but not private,
and information gathering requires no interaction with the person who
posted it online, then the research is unlikely to qualify as human
subjects research.
Defining features of human subject research, according to federal
regulations, are that the researchers interact directly with the subject
or obtain identifiable private information about the subject. Social media research may or may not meet this definition. A research institution's institutional review board
(IRB) is often responsible for reviewing potential research on human
subjects, but IRB protocols regarding social media research may be vague
or outdated.
Concerns regarding privacy and informed consent have surfaced regarding multiple social media studies. A research project by Harvard sociologists, known as "Tastes, Ties, and Time," utilized data from Facebook
profiles of students at an “anonymous, northeastern American
university” that was quickly identified as Harvard, potentially placing
the privacy of the human subjects at risk. The data set was removed from public access shortly after the issue was identified. The issue was complicated by the fact that the research project was partially funded by the National Science Foundation, which mandates the projects it funds to engage in data sharing.
A study by Facebook and researchers at Cornell University, published in the Proceedings of the National Academy of Sciences
in 2014, collected data from hundreds of thousands of Facebook users
after temporarily removing certain types of emotional content from their
News Feed. Many considered this a violation of the requirement for informed consent in human subjects research.
Because the data was collected by Facebook, a private company, in a
manner that was consistent with its Data Use Policy and user terms and
agreements, the Cornell IRB board determined that the study did not fall
under its jurisdiction. It has been argued that this study broke the law nonetheless by violating state laws regarding informed consent.
Others have noted that speaking out against these research methods may
be counterproductive, as private companies will likely continue to
experiment on users, but will be dis-incentivized from sharing their
methods or findings with scientists or the public.
In an “Editorial Expression of Concern” that was added to the online
version of the research paper, PNAS states that while they “deemed it
appropriate to publish the paper... It is nevertheless a matter of
concern that the collection of the data by Facebook may have involved
practices that were not fully consistent with the principles of
obtaining informed consent and allowing participants to opt out.”
Moreno et al.’s recommended considerations for social media
research are: 1) determine if the study qualifies as human subject
research, 2) consider the risk level of the content, 3) present research
and motives accurately when engaging on social media, 4) provide
contact information throughout the consent process, 5) make sure data is
not identifiable or searchable (avoid direct quotes that may be
identifiable with an online search), 6) consider developing project
privacy policies in advance, and 7) be aware that each state has its own
laws regarding informed consent.
Social media sites offer great potential as a data source by providing
access to hard-to-reach research subjects and groups, capturing the
natural, “real-world” responses of subjects, and providing affordable
and efficient data collection methods.
Nazi Germany performed human experimentation on large numbers of prisoners (including children), largely Jews from across Europe, but also Romani, Sinti, ethnic Poles, Soviet POWs and disabled Germans, by Nazi Germany in its concentration camps mainly in the early 1940s, during World War II and the Holocaust. Prisoners were forced into participating; they did not willingly volunteer and no consent was given for the procedures. Typically, the experiments resulted in death, trauma, disfigurement or permanent disability, and as such are considered as examples of medical torture. After the war, these crimes were tried at what became known as the Doctors' Trial, and the abuses perpetrated led to the development of the Nuremberg Code. During the Nuremberg Trials,
23 Nazi doctors and scientists were prosecuted for the unethical
treatment of concentration camp inmates, who were often used as research
subjects with fatal consequences. Of those 23, 15 were convicted, 7
were condemned to death, 9 received prison sentences from 10 years to
life, and 7 were acquitted.
During World War II, Fort Detrick in Maryland was the headquarters of US biological warfare experiments. Operation Whitecoat involved the injection of infectious agents into military forces to observe their effects in human subjects. Subsequent human experiments in the United States have also been characterized as unethical. They were often performed illegally, without the knowledge, consent, or informed consent
of the test subjects. Public outcry over the discovery of government
experiments on human subjects led to numerous congressional
investigations and hearings, including the Church Committee, Rockefeller Commission, and Advisory Committee on Human Radiation Experiments, amongst others. The Tuskegee syphilis experiment, widely regarded as the "most infamous biomedical research study in U.S. history," was performed from 1932 to 1972 by the Tuskegee Institute contracted by the United States Public Health Service.
The study followed more than 600 African-American men who were not told
they had syphilis and were denied access to the known treatment of penicillin. This led to the 1974 National Research Act,
to provide for protection of human subjects in experiments. The
National Commission for the Protection of Human Subjects of Biomedical
and Behavioral Research was established and was tasked with establishing
the boundary between research and routine practice, the role of risk-benefit analysis, guidelines for participation, and the definition of informed consent. Its Belmont Report established three tenets of ethical research: respect for persons, beneficence, and justice.
From the 1950s-60s, Chester M. Southam, an important virologist and cancer researcher, injected HeLa cells into cancer patients, healthy individuals, and prison inmates from the Ohio Penitentiary.
He wanted to observe if cancer could be transmitted as well as if
people could become immune to cancer by developing an acquired immune
response. Many believe that this experiment violated the bioethical
principles of informed consent, non-maleficence, and beneficence.
Animal testing, also known as animal experimentation, animal research and in vivo testing,
is the use of non-human animals in experiments that seek to control the
variables that affect the behavior or biological system under study.
This approach can be contrasted with field studies in which animals are
observed in their natural environments or habitats. Experimental
research with animals is usually conducted in universities, medical
schools, pharmaceutical companies, defense establishments and commercial
facilities that provide animal-testing services to industry.
The focus of animal testing varies on a continuum from pure research,
focusing on developing fundamental knowledge of an organism, to applied
research, which may focus on answering some question of great practical
importance, such as finding a cure for a disease. Examples of applied
research include testing disease treatments, breeding, defense research
and toxicology, including cosmetics testing.
In education, animal testing is sometimes a component of biology or
psychology courses. The practice is regulated to varying degrees in
different countries.
It is estimated that the annual use of vertebrate animals—from zebrafish to non-human primates—ranges from tens to more than 100 million.
In the European Union, vertebrate species represent 93% of animals used
in research, and 11.5 million animals were used there in 2011. By one
estimate the number of mice and rats used in the United States alone in
2001 was 80 million. Mice, rats, fish, amphibians and reptiles together account for over 85% of research animals.
Most animals are euthanized after being used in an experiment. Sources of laboratory animals
vary between countries and species; most animals are purpose-bred,
while a minority are caught in the wild or supplied by dealers who
obtain them from auctions and pounds. Supporters of the use of animals in experiments, such as the British Royal Society, argue that virtually every medical achievement in the 20th century relied on the use of animals in some way. The Institute for Laboratory Animal Research of the United States National Academy of Sciences
has argued that animal research cannot be replaced by even
sophisticated computer models, which are unable to deal with the
extremely complex interactions between molecules, cells, tissues,
organs, organisms and the environment. Animal rights organizations—such as PETA and BUAV—question the need for and legitimacy of animal testing, arguing that it is cruel
and poorly regulated, that medical progress is actually held back by
misleading animal models that cannot reliably predict effects in humans,
that some of the tests are outdated, that the costs outweigh the
benefits, or that animals have the intrinsic right not to be used or
harmed in experimentation.
Definitions
The terms animal testing, animal experimentation, animal research, in vivo testing, and vivisection have similar denotations but different connotations.
Literally, "vivisection" means "live sectioning" of an animal, and
historically referred only to experiments that involved the dissection of live animals. The term is occasionally used to refer pejoratively to any experiment using living animals; for example, the Encyclopædia Britannica
defines "vivisection" as: "Operation on a living animal for
experimental rather than healing purposes; more broadly, all
experimentation on live animals", although dictionaries point out that the broader definition is "used only by people who are opposed to such work". The word has a negative connotation, implying torture, suffering, and death.
The word "vivisection" is preferred by those opposed to this research,
whereas scientists typically use the term "animal experimentation".
The earliest references to animal testing are found in the writings of the Greeks in the 2nd and 4th centuries BC. Aristotle and Erasistratus were among the first to perform experiments on living animals. Galen, a 2nd-century Roman physician, dissected pigs and goats; he is known as the "father of vivisection". Avenzoar, a 12th-century Arabic physician in Moorish Spain
also practiced dissection; he introduced animal testing as an
experimental method of testing surgical procedures before applying them
to human patients.
Animals have repeatedly been used through the history of biomedical research. In 1831, the founders of the Dublin Zoo were members of the medical profession who were interested in studying animals while they were alive and when they were dead. In the 1880s, Louis Pasteur convincingly demonstrated the germ theory of medicine by inducing anthrax in sheep. In the 1880s, Robert Koch infected mice and guinea pigs with anthrax and tuberculosis. In the 1890s, Ivan Pavlov famously used dogs to describe classical conditioning. In World War I, German agents infected sheep bound for Russia with anthrax, and inoculated mules and horses of the French cavalry with the equine glanders
disease. Between 1917 and 1918, the Germans infected mules in Argentina
bound for American forces, resulting in the death of 200 mules. Insulin was first isolated from dogs in 1922, and revolutionized the treatment of diabetes. On 3 November 1957, a Soviet dog, Laika, became the first of many animals to orbit the earth. In the 1970s, antibiotic treatments and vaccines for leprosy were developed using armadillos, then given to humans. The ability of humans to change the genetics of animals took a large step forwards in 1974 when Rudolf Jaenisch was able to produce the first transgenic mammal, by integrating DNA from the SV40 virus into the genome of mice. This genetic research progressed rapidly and, in 1996, Dolly the sheep was born, the first mammal to be cloned from an adult cell.
Toxicology
testing became important in the 20th century. In the 19th century, laws
regulating drugs were more relaxed. For example, in the US, the
government could only ban a drug after a company had been prosecuted for
selling products that harmed customers. However, in response to the Elixir Sulfanilamide disaster
of 1937 in which the eponymous drug killed more than 100 users, the US
Congress passed laws that required safety testing of drugs on animals
before they could be marketed. Other countries enacted similar
legislation. In the 1960s, in reaction to the Thalidomide tragedy, further laws were passed requiring safety testing on pregnant animals before a drug can be sold.
Historical debate
Claude Bernard, regarded as the "prince of vivisectors", argued that experiments on animals are "entirely conclusive for the toxicology and hygiene of man".
As the experimentation on animals increased, especially the practice
of vivisection, so did criticism and controversy. In 1655, the advocate
of Galenic physiology Edmund O'Meara said that "the miserable torture of vivisection places the body in an unnatural state".
O'Meara and others argued that animal physiology could be affected by
pain during vivisection, rendering results unreliable. There were also
objections on an ethical basis, contending that the benefit to humans did not justify the harm to animals.
Early objections to animal testing also came from another angle—many
people believed that animals were inferior to humans and so different
that results from animals could not be applied to humans.
On the other side of the debate, those in favor of animal testing
held that experiments on animals were necessary to advance medical and
biological knowledge. Claude Bernard—who is sometimes known as the "prince of vivisectors"
and the father of physiology, and whose wife, Marie Françoise Martin,
founded the first anti-vivisection society in France in 1883—famously
wrote in 1865 that "the science of life is a superb and dazzlingly
lighted hall which may be reached only by passing through a long and
ghastly kitchen".
Arguing that "experiments on animals ... are entirely conclusive for
the toxicology and hygiene of man...the effects of these substances are
the same on man as on animals, save for differences in degree", Bernard established animal experimentation as part of the standard scientific method.
In 1896, the physiologist and physician Dr. Walter B. Cannon
said "The antivivisectionists are the second of the two types Theodore
Roosevelt described when he said, 'Common sense without conscience may
lead to crime, but conscience without common sense may lead to folly,
which is the handmaiden of crime.'" These divisions between pro- and anti-animal testing groups first came to public attention during the Brown Dog affair
in the early 1900s, when hundreds of medical students clashed with
anti-vivisectionists and police over a memorial to a vivisected dog.
One of Pavlov's dogs with a saliva-catch container and tube surgically implanted in his muzzle, Pavlov Museum, 2005
In 1822, the first animal protection law was enacted in the British parliament, followed by the Cruelty to Animals Act (1876), the first law specifically aimed at regulating animal testing. The legislation was promoted by Charles Darwin, who wrote to Ray Lankester
in March 1871: "You ask about my opinion on vivisection. I quite agree
that it is justifiable for real investigations on physiology; but not
for mere damnable and detestable curiosity. It is a subject which makes
me sick with horror, so I will not say another word about it, else I
shall not sleep to-night." In response to the lobbying by anti-vivisectionists, several organizations were set up in Britain to defend animal research: The Physiological Society was formed in 1876 to give physiologists "mutual benefit and protection", the Association for the Advancement of Medicine by Research was formed in 1882 and focused on policy-making, and the Research Defence Society (now Understanding Animal Research)
was formed in 1908 "to make known the facts as to experiments on
animals in this country; the immense importance to the welfare of
mankind of such experiments and the great saving of human life and
health directly attributable to them".
Opposition to the use of animals in medical research first arose in the United States during the 1860s, when Henry Bergh founded the American Society for the Prevention of Cruelty to Animals
(ASPCA), with America's first specifically anti-vivisection
organization being the American AntiVivisection Society (AAVS), founded
in 1883. Antivivisectionists of the era generally believed the spread of
mercy was the great cause of civilization, and vivisection was cruel.
However, in the USA the antivivisectionists' efforts were defeated in
every legislature, overwhelmed by the superior organization and
influence of the medical community. Overall, this movement had little
legislative success until the passing of the Laboratory Animal Welfare
Act, in 1966.
1some methods of testing are excluded from the ban or the laws vary within the country
The regulations that apply to animals in laboratories vary across species. In the U.S., under the provisions of the Animal Welfare Act and the Guide for the Care and Use of Laboratory Animals (the Guide),
published by the National Academy of Sciences, any procedure can be
performed on an animal if it can be successfully argued that it is
scientifically justified. In general, researchers are required to
consult with the institution's veterinarian and its Institutional Animal Care and Use Committee (IACUC), which every research facility is obliged to maintain.
The IACUC must ensure that alternatives, including non-animal
alternatives, have been considered, that the experiments are not
unnecessarily duplicative, and that pain relief is given unless it would
interfere with the study. The IACUCs regulate all vertebrates in
testing at institutions receiving federal funds in the USA. Although the
provisions of the Animal Welfare Act do not include purpose-bred
rodents and birds, these species are equally regulated under Public
Health Service policies that govern the IACUCs.
The Public Health Service policy oversees the Food and Drug
Administration (FDA) and the Centers for Disease Control and Prevention
(CDC). The CDC conducts infectious disease research on nonhuman
primates, rabbits, mice, and other animals, while FDA requirements cover
use of animals in pharmaceutical research.
Animal Welfare Act (AWA) regulations are enforced by the USDA, whereas
Public Health Service regulations are enforced by OLAW and in many cases
by AAALAC.
According to the 2014 U.S. Department of Agriculture Office of
the Inspector General (OIG) report—which looked at the oversight of
animal use during a three-year period—"some Institutional Animal Care
and Use Committees ...did not adequately approve, monitor, or report on
experimental procedures on animals". The OIG found that "as a result,
animals are not always receiving basic humane care and treatment and, in
some cases, pain and distress are not minimized during and after
experimental procedures". According to the report, within a three-year
period, nearly half of all American laboratories with regulated species
were cited for AWA violations relating to improper IACUC oversight. The USDA OIG made similar findings in a 2005 report.
With only a broad number of 120 inspectors, the United States
Department of Agriculture (USDA) oversees more than 12,000 facilities
involved in research, exhibition, breeding, or dealing of animals.
Others have criticized the composition of IACUCs, asserting that the
committees are predominantly made up of animal researchers and
university representatives who may be biased against animal welfare
concerns.
Larry Carbone, a laboratory animal veterinarian, writes that, in
his experience, IACUCs take their work very seriously regardless of the
species involved, though the use of non-human primates always raises what he calls a "red flag of special concern". A study published in Science
magazine in July 2001 confirmed the low reliability of IACUC reviews of
animal experiments. Funded by the National Science Foundation, the
three-year study found that animal-use committees that do not know the
specifics of the university and personnel do not make the same approval
decisions as those made by animal-use committees that do know the
university and personnel. Specifically, blinded committees more often
ask for more information rather than approving studies.
Scientists in India are protesting a recent guideline issued by the University Grants Commission to ban the use of live animals in universities and laboratories.
Numbers
Accurate
global figures for animal testing are difficult to obtain; it has been
estimated that 100 million vertebrates are experimented on around the
world every year, 10–11 million of them in the EU. The Nuffield Council on Bioethics
reports that global annual estimates range from 50 to 100 million
animals. None of the figures include invertebrates such as shrimp and
fruit flies.
The USDA/APHIS has published the 2016 animal research statistics.
Overall, the number of animals (covered by the Animal Welfare Act) used
in research in the US rose 6.9% from 767,622 (2015) to 820,812 (2016). This includes both public and private institutions. By comparing with EU data, where all vertebrate species are counted, Speaking of Research estimated that around 12 million vertebrates were used in research in the US in 2016. A 2015 article published in the Journal of Medical Ethics,
argued that the use of animals in the US has dramatically increased in
recent years. Researchers found this increase is largely the result of
an increased reliance on genetically modified mice in animal studies.
In 1995, researchers at Tufts University Center for Animals and
Public Policy estimated that 14–21 million animals were used in American
laboratories in 1992, a reduction from a high of 50 million used in
1970.
In 1986, the U.S. Congress Office of Technology Assessment reported
that estimates of the animals used in the U.S. range from 10 million to
upwards of 100 million each year, and that their own best estimate was
at least 17 million to 22 million.
In 2016, the Department of Agriculture listed 60,979 dogs, 18,898 cats,
71,188 non-human primates, 183,237 guinea pigs, 102,633 hamsters,
139,391 rabbits, 83,059 farm animals, and 161,467 other mammals, a total
of 820,812, a figure that includes all mammals except purpose-bred mice
and rats. The use of dogs and cats in research in the U.S. decreased
from 1973 to 2016 from 195,157 to 60,979, and from 66,165 to 18,898,
respectively.
In the UK, Home Office figures show that 3.79 million procedures were carried out in 2017.
2,960 procedures used non-human primates, down over 50% since 1988. A
"procedure" refers here to an experiment that might last minutes,
several months, or years. Most animals are used in only one procedure:
animals are frequently euthanized after the experiment; however death is
the endpoint of some procedures.
The procedures conducted on animals in the UK in 2017 were categorised as –
43% (1.61 million) were assessed as sub-threshold
4% (0.14 million) were assessed as non-recovery
36% (1.35 million) were assessed as mild
15% (0.55 million) were assessed as moderate
4% (0.14 million) were assessed as severe
A 'severe' procedure would be, for instance, any test where death is
the end-point or fatalities are expected, whereas a 'mild' procedure
would be something like a blood test or an MRI scan.
The Three Rs
The Three Rs (3Rs) are guiding principles for more ethical use of
animals in testing. These were first described by W.M.S. Russell and
R.L. Burch in 1959. The 3Rs state:
Replacement which refers to the preferred use of non-animal
methods over animal methods whenever it is possible to achieve the same
scientific aims. These methods include computer modeling.
Reduction which refers to methods that enable researchers to obtain
comparable levels of information from fewer animals, or to obtain more
information from the same number of animals.
Refinement which refers to methods that alleviate or minimize
potential pain, suffering or distress, and enhance animal welfare for
the animals used. These methods include non-invasive techniques.
The 3Rs have a broader scope than simply encouraging alternatives to
animal testing, but aim to improve animal welfare and scientific quality
where the use of animals can not be avoided. These 3Rs are now
implemented in many testing establishments worldwide and have been
adopted by various pieces of legislation and regulations.
Despite the widespread acceptance of the 3Rs, many
countries—including Canada, Australia, Israel, South Korea, and
Germany—have reported rising experimental use of animals in recent years
with increased use of mice and, in some cases, fish while reporting
declines in the use of cats, dogs, primates, rabbits, guinea pigs, and
hamsters. Along with other countries, China has also escalated its use
of GM animals, resulting in an increase in overall animal use.
Invertebrates
Fruit flies are an invertebrate commonly used in animal testing.
Although many more invertebrates than vertebrates are used in animal
testing, these studies are largely unregulated by law. The most
frequently used invertebrate species are Drosophila melanogaster, a fruit fly, and Caenorhabditis elegans, a nematode worm. In the case of C. elegans, the worm's body is completely transparent and the precise lineage of all the organism's cells is known, while studies in the fly D. melanogaster can use an amazing array of genetic tools.
These invertebrates offer some advantages over vertebrates in animal
testing, including their short life cycle and the ease with which large
numbers may be housed and studied. However, the lack of an adaptive immune system and their simple organs prevent worms from being used in several aspects of medical research such as vaccine development. Similarly, the fruit fly immune system differs greatly from that of humans, and diseases in insects can be different from diseases in vertebrates; however, fruit flies and waxworms can be useful in studies to identify novel virulence factors or pharmacologically active compounds.
Several invertebrate systems are considered acceptable alternatives to vertebrates in early-stage discovery screens.
Because of similarities between the innate immune system of insects and
mammals, insects can replace mammals in some types of studies. Drosophila melanogaster and the Galleria mellonella waxworm have been particularly important for analysis of virulence traits of mammalian pathogens.
Waxworms and other insects have also proven valuable for the
identification of pharmaceutical compounds with favorable
bioavailability.
The decision to adopt such models generally involves accepting a lower
degree of biological similarity with mammals for significant gains in
experimental throughput.
This rat is being deprived of rapid eye-movement (REM) sleep using a single platform ("flower pot") technique.
The water is within 1 cm of the small flower pot bottom platform where
the rat sits. The rat is able to sleep but at the onset of REM sleep
muscle tone is lost and the rat would either fall into the water only to
clamber back to the pot to avoid drowning, or its nose would become submerged into the water shocking it back to an awakened state.
In the U.S., the numbers of rats and mice used is estimated to be from 11 million to between 20 and 100 million a year.
Other rodents commonly used are guinea pigs, hamsters, and gerbils.
Mice are the most commonly used vertebrate species because of their
size, low cost, ease of handling, and fast reproduction rate. Mice are widely considered to be the best model of inherited human disease and share 95% of their genes with humans. With the advent of genetic engineering technology, genetically modified mice can be generated to order and can provide models for a range of human diseases.
Rats are also widely used for physiology, toxicology and cancer
research, but genetic manipulation is much harder in rats than in mice,
which limits the use of these rodents in basic science.
Over 500,000 fish and 9,000 amphibians were used in the UK in 2016. The main species used is the zebrafish, Danio rerio, which are translucent during their embryonic stage, and the African clawed frog, Xenopus laevis. Over 20,000 rabbits were used for animal testing in the UK in 2004. Albino rabbits are used in eye irritancy tests (Draize test)
because rabbits have less tear flow than other animals, and the lack of
eye pigment in albinos make the effects easier to visualize. The
numbers of rabbits used for this purpose has fallen substantially over
the past two decades. In 1996, there were 3,693 procedures on rabbits
for eye irritation in the UK, and in 2017 this number was just 63. Rabbits are also frequently used for the production of polyclonal antibodies.
Cats
Cats are most commonly used in neurological research. In 2016, 18,898 cats were used in the United States alone, around a third of which were used in experiments which have the potential to cause "pain and/or distress"
though only 0.1% of cat experiments involved potential pain which was
not relieved by anesthetics/analgesics. In the UK, just 198 procedures
were carried out on cats in 2017. The number has been around 200 for
most of the last decade.
Dogs
Dogs are widely used in biomedical research, testing, and education—particularly beagles,
because they are gentle and easy to handle, and to allow for
comparisons with historical data from beagles (a Reduction
technique).(citation needed) They are used as models for human and
veterinary diseases in cardiology, endocrinology, and bone and joint studies, research that tends to be highly invasive, according to the Humane Society of the United States. The most common use of dogs is in the safety assessment of new medicines
for human or veterinary use as a second species following testing in
rodents, in accordance with the regulations set out in the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use.
One of the most significant advancements in medical science involves
the use of dogs in developing the answers to insulin production in the
body for diabetics and the role of the pancreas in this process. They
found that the pancreas was responsible for producing insulin in the
body and that removal of the pancreas, resulted in the development of
diabetes in the dog. After re-injecting the pancreatic extract,
(insulin), the blood glucose levels were significantly lowered.
The advancements made in this research involving the use of dogs has
resulted in a definite improvement in the quality of life for both
humans and animals.
The U.S. Department of Agriculture's Animal Welfare Report shows
that 60,979 dogs were used in USDA-registered facilities in 2016. In the UK, according to the UK Home Office, there were 3,847 procedures on dogs in 2017. Of the other large EU users of dogs, Germany conducted 3,976 procedures on dogs in 2016 and France conducted 4,204 procedures in 2016. In both cases this represents under 0.2% of the total number of procedures conducted on animals in the respective countries.
Non-human primates
Non-human primates (NHPs) are used in toxicology tests, studies of AIDS and hepatitis, studies of neurology, behavior and cognition, reproduction, genetics, and xenotransplantation.
They are caught in the wild or purpose-bred. In the United States and
China, most primates are domestically purpose-bred, whereas in Europe
the majority are imported purpose-bred. The European Commission reported that in 2011, 6,012 monkeys were experimented on in European laboratories. According to the U.S. Department of Agriculture, there were 71,188 monkeys in U.S. laboratories in 2016. 23,465 monkeys were imported into the U.S. in 2014 including 929 who were caught in the wild. Most of the NHPs used in experiments are macaques; but marmosets, spider monkeys, and squirrel monkeys are also used, and baboons and chimpanzees are used in the US. As of 2015, there are approximately 730 chimpanzees in U.S. laboratories.
In a survey in 2003, it was found that 89% of singly-housed primates exhibited self-injurious or abnormalstereotypyical behaviors including pacing, rocking, hair pulling, and biting among others.
The first transgenic primate was produced in 2001, with the development of a method that could introduce new genes into a rhesus macaque. This transgenic technology is now being applied in the search for a treatment for the genetic disorderHuntington's disease. Notable studies on non-human primates have been part of the polio vaccine development, and development of Deep Brain Stimulation, and their current heaviest non-toxicological use occurs in the monkey AIDS model, SIV. In 2008 a proposal to ban all primates experiments in the EU has sparked a vigorous debate.
Sources
Animals used by laboratories are largely supplied by specialist
dealers. Sources differ for vertebrate and invertebrate animals. Most
laboratories breed and raise flies and worms themselves, using strains
and mutants supplied from a few main stock centers. For vertebrates, sources include breeders and dealers like Covance and Charles River Laboratories who supply purpose-bred and wild-caught animals; businesses that trade in wild animals such as Nafovanny; and dealers who supply animals sourced from pounds, auctions, and newspaper ads. Animal shelters also supply the laboratories directly. Large centers also exist to distribute strains of genetically modified animals; the International Knockout Mouse Consortium, for example, aims to provide knockout mice for every gene in the mouse genome.
A laboratory mouse cage. Mice are either bred commercially, or raised in the laboratory.
In the U.S., Class A breeders are licensed by the U.S. Department of
Agriculture (USDA) to sell animals for research purposes, while Class B
dealers are licensed to buy animals from "random sources" such as
auctions, pound seizure, and newspaper ads. Some Class B dealers have
been accused of kidnapping pets and illegally trapping strays, a
practice known as bunching.
It was in part out of public concern over the sale of pets to research
facilities that the 1966 Laboratory Animal Welfare Act was ushered
in—the Senate Committee on Commerce reported in 1966 that stolen pets
had been retrieved from Veterans Administration facilities, the Mayo
Institute, the University of Pennsylvania, Stanford University, and
Harvard and Yale Medical Schools. The USDA recovered at least a dozen stolen pets during a raid on a Class B dealer in Arkansas in 2003.
Four states in the U.S.—Minnesota, Utah, Oklahoma, and Iowa—require
their shelters to provide animals to research facilities. Fourteen
states explicitly prohibit the practice, while the remainder either
allow it or have no relevant legislation.
In the European Union, animal sources are governed by Council Directive 86/609/EEC,
which requires lab animals to be specially bred, unless the animal has
been lawfully imported and is not a wild animal or a stray. The latter
requirement may also be exempted by special arrangement. In 2010 the Directive was revised with EU Directive 2010/63/EU.
In the UK, most animals used in experiments are bred for the purpose
under the 1988 Animal Protection Act, but wild-caught primates may be
used if exceptional and specific justification can be established.
The United States also allows the use of wild-caught primates; between
1995 and 1999, 1,580 wild baboons were imported into the U.S. Over half
the primates imported between 1995 and 2000 were handled by Charles River Laboratories, or by Covance, which is the single largest importer of primates into the U.S.
No official recognition of animal sentience or suffering
Unknown
1certain animals are excluded, only mental health is acknowledged, and/or the laws vary internally 2only includes domestic animals
The extent to which animal testing causes pain and suffering, and the capacity of animals to experience and comprehend them, is the subject of much debate.
According to the USDA, in 2016 501,560 animals (61%) (not
including rats, mice, birds, or invertebrates) were used in procedures
that did not include more than momentary pain or distress. 247,882 (31%)
animals were used in procedures in which pain or distress was relieved
by anesthesia, while 71,370 (9%) were used in studies that would cause
pain or distress that would not be relieved.
Since 2014, in the UK, every research procedure was
retrospectively assessed for severity. The five categories are
"sub-threshold", "mild", "moderate", "severe" and "non-recovery", the
latter being procedures in which an animal is anesthetized and subsequently killed without recovering consciousness.
In 2017, 43% (1.61 million) were assessed as sub-threshold, 4% (0.14
million) were assessed as non-recovery, 36% (1.35 million) were assessed
as mild, 15% (0.55 million) were assessed as moderate and 4% (0.14
million) were assessed as severe.
The idea that animals might not feel pain as human beings feel it traces back to the 17th-century French philosopher, René Descartes, who argued that animals do not experience pain and suffering because they lack consciousness. Bernard Rollin of Colorado State University, the principal author of two U.S. federal laws regulating pain relief for animals,
writes that researchers remained unsure into the 1980s as to whether
animals experience pain, and that veterinarians trained in the U.S.
before 1989 were simply taught to ignore animal pain.
In his interactions with scientists and other veterinarians, he was
regularly asked to "prove" that animals are conscious, and to provide
"scientifically acceptable" grounds for claiming that they feel pain.
Carbone writes that the view that animals feel pain differently is now a
minority view. Academic reviews of the topic are more equivocal, noting
that although the argument that animals have at least simple conscious
thoughts and feelings has strong support, some critics continue to question how reliably animal mental states can be determined.
However, some canine experts are stating that, while intelligence does
differ animal to animal, dogs have the intelligence of a two to
two-and-a-half-year old. This does support the idea that dogs, at the
very least, have some form of consciousness.
The ability of invertebrates to experience pain and suffering is less
clear, however, legislation in several countries (e.g. U.K., New Zealand, Norway) protects some invertebrate species if they are being used in animal testing.
In the U.S., the defining text on animal welfare regulation in animal testing is the Guide for the Care and Use of Laboratory Animals.
This defines the parameters that govern animal testing in the U.S. It
states "The ability to experience and respond to pain is widespread in
the animal kingdom...Pain is a stressor and, if not relieved, can lead
to unacceptable levels of stress and distress in animals." The Guide
states that the ability to recognize the symptoms of pain in different
species is vital in efficiently applying pain relief and that it is
essential for the people caring for and using animals to be entirely
familiar with these symptoms. On the subject of analgesics used to
relieve pain, the Guide states "The selection of the most appropriate
analgesic or anesthetic should reflect professional judgment as to which
best meets clinical and humane requirements without compromising the
scientific aspects of the research protocol". Accordingly, all issues of
animal pain and distress, and their potential treatment with analgesia
and anesthesia, are required regulatory issues in receiving animal
protocol approval.
In 2019, Katrien Devolder and Matthias Eggel proposed gene editing research animals to remove the ability to feel pain. This would be an intermediate step towards eventually stopping all experimentation on animals and adopting alternatives. Additionally, this would not stop research animals from experiencing psychological harm.
Euthanasia
Regulations require that scientists use as few animals as possible, especially for terminal experiments.
However, while policy makers consider suffering to be the central issue
and see animal euthanasia as a way to reduce suffering, others, such as
the RSPCA, argue that the lives of laboratory animals have intrinsic value. Regulations focus on whether particular methods cause pain and suffering, not whether their death is undesirable in itself. The animals are euthanized at the end of studies for sample collection or post-mortem examination;
during studies if their pain or suffering falls into certain categories
regarded as unacceptable, such as depression, infection that is
unresponsive to treatment, or the failure of large animals to eat for
five days; or when they are unsuitable for breeding or unwanted for some other reason.
Methods of euthanizing laboratory animals are chosen to induce rapid unconsciousness and death without pain or distress.
The methods that are preferred are those published by councils of
veterinarians. The animal can be made to inhale a gas, such as carbon monoxide and carbon dioxide, by being placed in a chamber, or by use of a face mask, with or without prior sedation or anesthesia. Sedatives or anesthetics such as barbiturates can be given intravenously, or inhalant anesthetics may be used. Amphibians and fish may be immersed in water containing an anesthetic such as tricaine. Physical methods are also used, with or without sedation or anesthesia depending on the method. Recommended methods include decapitation (beheading) for small rodents or rabbits. Cervical dislocation (breaking the neck or spine) may be used for birds, mice, and immature rats and rabbits. High-intensity microwave irradiation of the brain can preserve brain tissue and induce death in less than 1 second, but this is currently only used on rodents. Captive bolts
may be used, typically on dogs, ruminants, horses, pigs and rabbits. It
causes death by a concussion to the brain. Gunshot may be used, but
only in cases where a penetrating captive bolt may not be used. Some
physical methods are only acceptable after the animal is unconscious. Electrocution may be used for cattle, sheep, swine, foxes, and mink after the animals are unconscious, often by a prior electrical stun. Pithing (inserting a tool into the base of the brain) is usable on animals already unconscious. Slow or rapid freezing, or inducing air embolism are acceptable only with prior anesthesia to induce unconsciousness.
Research classification
Pure research
Basic
or pure research investigates how organisms behave, develop, and
function. Those opposed to animal testing object that pure research may
have little or no practical purpose, but researchers argue that it forms
the necessary basis for the development of applied research, rendering
the distinction between pure and applied research—research that has a
specific practical aim—unclear.
Pure research uses larger numbers and a greater variety of animals than
applied research. Fruit flies, nematode worms, mice and rats together
account for the vast majority, though small numbers of other species are
used, ranging from sea slugs through to armadillos. Examples of the types of animals and experiments used in basic research include:
Studies on embryogenesis and developmental biology. Mutants are created by adding transposons into their genomes, or specific genes are deleted by gene targeting.
By studying the changes in development these changes produce,
scientists aim to understand both how organisms normally develop, and
what can go wrong in this process. These studies are particularly
powerful since the basic controls of development, such as the homeobox genes, have similar functions in organisms as diverse as fruit flies and man.
Experiments into behavior, to understand how organisms detect
and interact with each other and their environment, in which fruit
flies, worms, mice, and rats are all widely used. Studies of brain function, such as memory and social behavior, often use rats and birds. For some species, behavioral research is combined with enrichment strategies for animals in captivity because it allows them to engage in a wider range of activities.
Breeding experiments to study evolution and genetics. Laboratory mice, flies, fish, and worms are inbred through many generations to create strains with defined characteristics.
These provide animals of a known genetic background, an important tool
for genetic analyses. Larger mammals are rarely bred specifically for
such studies due to their slow rate of reproduction, though some
scientists take advantage of inbred domesticated animals, such as dog or cattle breeds, for comparative
purposes. Scientists studying how animals evolve use many animal
species to see how variations in where and how an organism lives (their niche) produce adaptations in their physiology and morphology. As an example, sticklebacks
are now being used to study how many and which types of mutations are
selected to produce adaptations in animals' morphology during the
evolution of new species.
Applied research
Applied research aims to solve specific and practical problems. These may involve the use of animal models
of diseases or conditions, which are often discovered or generated by
pure research programmes. In turn, such applied studies may be an early
stage in the drug discovery process. Examples include:
Genetic modification
of animals to study disease. Transgenic animals have specific genes
inserted, modified or removed, to mimic specific conditions such as single gene disorders, such as Huntington's disease. Other models mimic complex, multifactorial diseases with genetic components, such as diabetes, or even transgenic mice that carry the same mutations that occur during the development of cancer.
These models allow investigations on how and why the disease develops,
as well as providing ways to develop and test new treatments.
The vast majority of these transgenic models of human disease are lines
of mice, the mammalian species in which genetic modification is most
efficient. Smaller numbers of other animals are also used, including rats, pigs, sheep, fish, birds, and amphibians.
Studies on models of naturally occurring disease and condition.
Certain domestic and wild animals have a natural propensity or
predisposition for certain conditions that are also found in humans.
Cats are used as a model to develop immunodeficiency virus vaccines and
to study leukemia because their natural predisposition to FIV and Feline leukemia virus. Certain breeds of dog suffer from narcolepsy making them the major model used to study the human condition. Armadillos and humans are among only a few animal species that naturally suffer from leprosy; as the bacteria responsible for this disease cannot yet be grown in culture, armadillos are the primary source of bacilli used in leprosy vaccines.
Studies on induced animal models of human diseases. Here, an animal is treated so that it develops pathology and symptoms that resemble a human disease. Examples include restricting blood flow to the brain to induce stroke, or giving neurotoxins that cause damage similar to that seen in Parkinson's disease.
Much animal research into potential treatments for humans is wasted
because it is poorly conducted and not evaluated through systematic
reviews.
For example, although such models are now widely used to study
Parkinson's disease, the British anti-vivisection interest group BUAV argues that these models only superficially resemble the disease symptoms, without the same time course or cellular pathology. In contrast, scientists assessing the usefulness of animal models of Parkinson's disease, as well as the medical research charity The Parkinson's Appeal, state that these models were invaluable and that they led to improved surgical treatments such as pallidotomy, new drug treatments such as levodopa, and later deep brain stimulation.
Animal testing has also included the use of placebo
testing. In these cases animals are treated with a substance that
produces no pharmacological effect, but is administered in order to
determine any biological alterations due to the experience of a
substance being administered, and the results are compared with those
obtained with an active compound.
Xenotransplantation
Xenotransplantation
research involves transplanting tissues or organs from one species to
another, as a way to overcome the shortage of human organs for use in organ transplants.
Current research involves using primates as the recipients of organs
from pigs that have been genetically modified to reduce the primates' immune response against the pig tissue. Although transplant rejection remains a problem,
recent clinical trials that involved implanting pig insulin-secreting
cells into diabetics did reduce these people's need for insulin.
Documents released to the news media by the animal rights organization Uncaged Campaigns showed that, between 1994 and 2000, wild baboons imported to the UK from Africa by Imutran Ltd, a subsidiary of Novartis Pharma AG, in conjunction with Cambridge University and Huntingdon Life Sciences,
to be used in experiments that involved grafting pig tissues, suffered
serious and sometimes fatal injuries. A scandal occurred when it was
revealed that the company had communicated with the British government
in an attempt to avoid regulation.
Toxicology testing
Toxicology testing, also known as safety testing, is conducted by
pharmaceutical companies testing drugs, or by contract animal testing
facilities, such as Huntingdon Life Sciences, on behalf of a wide variety of customers.
According to 2005 EU figures, around one million animals are used every
year in Europe in toxicology tests; which are about 10% of all
procedures. According to Nature, 5,000 animals are used for each chemical being tested, with 12,000 needed to test pesticides. The tests are conducted without anesthesia, because interactions between drugs can affect how animals detoxify chemicals, and may interfere with the results.
Toxicology tests are used to examine finished products such as pesticides, medications, food additives, packing materials, and air freshener, or their chemical ingredients. Most tests involve testing ingredients rather than finished products, but according to BUAV,
manufacturers believe these tests overestimate the toxic effects of
substances; they therefore repeat the tests using their finished
products to obtain a less toxic label.
The substances are applied to the skin or dripped into the eyes; injected intravenously, intramuscularly, or subcutaneously;
inhaled either by placing a mask over the animals and restraining them,
or by placing them in an inhalation chamber; or administered orally,
through a tube into the stomach, or simply in the animal's food. Doses
may be given once, repeated regularly for many months, or for the
lifespan of the animal.
There are several different types of acute toxicity tests. The LD50
("Lethal Dose 50%") test is used to evaluate the toxicity of a
substance by determining the dose required to kill 50% of the test
animal population. This test was removed from OECD international guidelines in 2002, replaced by methods such as the fixed dose procedure, which use fewer animals and cause less suffering.
Abbott writes that, as of 2005, "the LD50 acute toxicity test ... still
accounts for one-third of all animal [toxicity] tests worldwide".
Irritancy can be measured using the Draize test,
where a test substance is applied to an animal's eyes or skin, usually
an albino rabbit. For Draize eye testing, the test involves observing
the effects of the substance at intervals and grading any damage or
irritation, but the test should be halted and the animal killed if it
shows "continuing signs of severe pain or distress". The Humane Society of the United States writes that the procedure can cause redness, ulceration, hemorrhaging, cloudiness, or even blindness.
This test has also been criticized by scientists for being cruel and
inaccurate, subjective, over-sensitive, and failing to reflect human
exposures in the real world. Although no accepted in vitro alternatives exist, a modified form of the Draize test called the low volume eye test may reduce suffering and provide more realistic results and this was adopted as the new standard in September 2009. However, the Draize test will still be used for substances that are not severe irritants.
The most stringent tests are reserved for drugs and foodstuffs.
For these, a number of tests are performed, lasting less than a month
(acute), one to three months (subchronic), and more than three months
(chronic) to test general toxicity (damage to organs), eye and skin
irritancy, mutagenicity, carcinogenicity, teratogenicity,
and reproductive problems. The cost of the full complement of tests is
several million dollars per substance and it may take three or four
years to complete.
These toxicity tests provide, in the words of a 2006 United States National Academy of Sciences report, "critical information for assessing hazard and risk potential". Animal tests may overestimate risk, with false positive results being a particular problem, but false positives appear not to be prohibitively common.
Variability in results arises from using the effects of high doses of
chemicals in small numbers of laboratory animals to try to predict the
effects of low doses in large numbers of humans.
Although relationships do exist, opinion is divided on how to use data
on one species to predict the exact level of risk in another.
Scientists face growing pressure to move away from using
traditional animal toxicity tests to determine whether manufactured
chemicals are safe.
Among variety of approaches to toxicity evaluation the ones which have
attracted increasing interests are in vitro cell-based sensing methods
applying fluorescence.
Cosmetics testing
The "Leaping Bunny" logo: Some products in Europe that are not tested on animals carry this symbol.
Cosmetics testing on animals is particularly controversial. Such
tests, which are still conducted in the U.S., involve general toxicity,
eye and skin irritancy, phototoxicity (toxicity triggered by ultraviolet light) and mutagenicity.
Cosmetics testing on animals is banned in India, the European Union, Israel and Norway while legislation in the U.S. and Brazil is currently considering similar bans.
In 2002, after 13 years of discussion, the European Union agreed to
phase in a near-total ban on the sale of animal-tested cosmetics by
2009, and to ban all cosmetics-related animal testing. France, which is
home to the world's largest cosmetics company, L'Oreal, has protested the proposed ban by lodging a case at the European Court of Justice in Luxembourg, asking that the ban be quashed.
The ban is also opposed by the European Federation for Cosmetics
Ingredients, which represents 70 companies in Switzerland, Belgium,
France, Germany, and Italy. In October 2014, India passed stricter laws that also ban the importation of any cosmetic products that are tested on animals.
Drug testing
Before
the early 20th century, laws regulating drugs were lax. Currently, all
new pharmaceuticals undergo rigorous animal testing before being
licensed for human use. Tests on pharmaceutical products involve:
toxicology tests, which gauge acute, sub-acute, and chronic toxicity.
Acute toxicity is studied by using a rising dose until signs of
toxicity become apparent. Current European legislation demands that
"acute toxicity tests must be carried out in two or more mammalian
species" covering "at least two different routes of administration".
Sub-acute toxicity is where the drug is given to the animals for four
to six weeks in doses below the level at which it causes rapid
poisoning, in order to discover if any toxic drug metabolites
build up over time. Testing for chronic toxicity can last up to two
years and, in the European Union, is required to involve two species of
mammals, one of which must be non-rodent.
efficacy studies, which test whether experimental drugs work by inducing the appropriate illness in animals. The drug is then administered in a double-blind controlled trial, which allows researchers to determine the effect of the drug and the dose-response curve.
Specific tests on reproductive function, embryonic toxicity, or carcinogenic potential can all be required by law, depending on the result of other studies and the type of drug being tested.
Education
It
is estimated that 20 million animals are used annually for educational
purposes in the United States including, classroom observational
exercises, dissections and live-animal surgeries. Frogs, fetal pigs, perch, cats, earthworms, grasshoppers, crayfish and starfish are commonly used in classroom dissections.
Alternatives to the use of animals in classroom dissections are widely
used, with many U.S. States and school districts mandating students be
offered the choice to not dissect. Citing the wide availability of alternatives and the decimation of local frog species, India banned dissections in 2014.
The Sonoran Arthropod Institute hosts an annual Invertebrates in
Education and Conservation Conference to discuss the use of
invertebrates in education. There also are efforts in many countries to find alternatives to using animals in education.
The NORINA database, maintained by Norecopa, lists products that may be
used as alternatives or supplements to animal use in education, and in
the training of personnel who work with animals. These include alternatives to dissection in schools. InterNICHE has a similar database and a loans system.
In November 2013, the U.S.-based company Backyard Brains released
for sale to the public what they call the "Roboroach", an "electronic
backpack" that can be attached to cockroaches. The operator is required to amputate a cockroach's antennae, use sandpaper to wear down the shell, insert a wire into the thorax, and then glue the electrodes and circuit board onto the insect's back. A mobile phone app can then be used to control it via Bluetooth.
It has been suggested that the use of such a device may be a teaching
aid that can promote interest in science. The makers of the "Roboroach"
have been funded by the National Institute of Mental Health and state that the device is intended to encourage children to become interested in neuroscience.
Defense
Animals are used by the military to develop weapons, vaccines, battlefield surgical techniques, and defensive clothing. For example, in 2008 the United States Defense Advanced Research Projects Agency used live pigs to study the effects of improvised explosive device explosions on internal organs, especially the brain.
In the US military, goats are commonly used to train combat medics.
(Goats have become the main animal species used for this purpose after
the Pentagon phased out using dogs for medical training in the 1980s.) While modern mannequins
used in medical training are quite efficient in simulating the behavior
of a human body, some trainees feel that "the goat exercise provide[s] a
sense of urgency that only real life trauma can provide". Nevertheless, in 2014, the U.S. Coast Guard announced that it would reduce the number of animals it uses in its training exercises by half after PETA
released video showing Guard members cutting off the limbs of
unconscious goats with tree trimmers and inflicting other injuries with a
shotgun, pistol, ax and a scalpel.
That same year, citing the availability of human simulators and other
alternatives, the Department of Defense announced it would begin
reducing the number of animals it uses in various training programs. In 2013, several Navy medical centers stopped using ferrets in intubation exercises after complaints from PETA.
Besides the United States, six out of 28 NATO countries,
including Poland and Denmark, use live animals for combat medic
training.
The
moral and ethical questions raised by performing experiments on animals
are subject to debate, and viewpoints have shifted significantly over
the 20th century.
There remain disagreements about which procedures are useful for which
purposes, as well as disagreements over which ethical principles apply
to which species.
A 2015 Gallup poll found that 67% of Americans were "very concerned" or "somewhat concerned" about animals used in research. A Pew poll taken the same year found 50% of American adults opposed the use of animals in research.
Still, a wide range of viewpoints exist. The view that animals have moral rights (animal rights) is a philosophical position proposed by Tom Regan,
among others, who argues that animals are beings with beliefs and
desires, and as such are the "subjects of a life" with moral value and
therefore moral rights.
Regan still sees ethical differences between killing human and
non-human animals, and argues that to save the former it is permissible
to kill the latter. Likewise, a "moral dilemma" view suggests that
avoiding potential benefit to humans is unacceptable on similar grounds,
and holds the issue to be a dilemma in balancing such harm to humans to
the harm done to animals in research. In contrast, an abolitionist view in animal rights
holds that there is no moral justification for any harmful research on
animals that is not to the benefit of the individual animal. Bernard Rollin
argues that benefits to human beings cannot outweigh animal suffering,
and that human beings have no moral right to use an animal in ways that
do not benefit that individual. Donald Watson has stated that vivisection and animal experimentation "is probably the cruelest of all Man's attack on the rest of Creation." Another prominent position is that of philosopher Peter Singer,
who argues that there are no grounds to include a being's species in
considerations of whether their suffering is important in utilitarian moral considerations. Malcolm Macleod and collaborators argue that most controlled animal studies do not employ randomization, allocation concealment, and blinding
outcome assessment, and that failure to employ these features
exaggerates the apparent benefit of drugs tested in animals, leading to a
failure to translate much animal research for human benefit.
Governments such as the Netherlands and New Zealand have
responded to the public's concerns by outlawing invasive experiments on
certain classes of non-human primates, particularly the great apes. In 2015, captive chimpanzees in the U.S. were added to the Endangered Species Act adding new road blocks to those wishing to experiment on them. Similarly, citing ethical considerations and the availability of alternative research methods, the U.S. NIH announced in 2013 that it would dramatically reduce and eventually phase out experiments on chimpanzees.
The British government has required that the cost to animals in an experiment be weighed against the gain in knowledge. Some medical schools and agencies in China, Japan, and South Korea have built cenotaphs for killed animals. In Japan there are also annual memorial services (Ireisai 慰霊祭) for animals sacrificed at medical school.
Dolly the sheep: the first clone produced from the somatic cells of an adult mammal
Various specific cases of animal testing have drawn attention,
including both instances of beneficial scientific research, and
instances of alleged ethical violations by those performing the tests.
The fundamental properties of muscle physiology were determined with work done using frog muscles (including the force generating mechanism of all muscle, the length-tension relationship, and the force-velocity curve), and frogs are still the preferred model organism due to the long survival of muscles in vitro and the possibility of isolating intact single-fiber preparations (not possible in other organisms). Modern physical therapy
and the understanding and treatment of muscular disorders is based on
this work and subsequent work in mice (often engineered to express
disease states such as muscular dystrophy). In February 1997 a team at the Roslin Institute in Scotland announced the birth of Dolly the sheep, the first mammal to be cloned from an adult somatic cell.
Concerns have been raised over the mistreatment of primates undergoing testing. In 1985 the case of Britches, a macaque monkey at the University of California, Riverside, gained public attention. He had his eyelids sewn shut and a sonar sensor on his head as part of an experiment to test sensory substitution devices for blind people. The laboratory was raided by Animal Liberation Front in 1985, removing Britches and 466 other animals.
The National Institutes of Health conducted an eight-month
investigation and concluded, however, that no corrective action was
necessary. During the 2000s other cases have made headlines, including experiments at the University of Cambridge and Columbia University in 2002. In 2004 and 2005, undercover footage of staff of Covance's, a contract research organization that provides animal testing services, Virginia lab was shot by People for the Ethical Treatment of Animals
(PETA). Following release of the footage, the U.S. Department of
Agriculture fined Covance $8,720 for 16 citations, three of which
involved lab monkeys; the other citations involved administrative issues
and equipment.
Threats to researchers
Threats of violence to animal researchers are not uncommon.
In 2006, a primate researcher at the University of California, Los Angeles
(UCLA) shut down the experiments in his lab after threats from animal
rights activists. The researcher had received a grant to use 30 macaque
monkeys for vision experiments; each monkey was anesthetized for a
single physiological experiment lasting up to 120 hours, and then
euthanized. The researcher's name, phone number, and address were posted on the website of the Primate Freedom Project. Demonstrations were held in front of his home. A Molotov cocktail
was placed on the porch of what was believed to be the home of another
UCLA primate researcher; instead, it was accidentally left on the porch
of an elderly woman unrelated to the university. The Animal Liberation Front claimed responsibility for the attack.
As a result of the campaign, the researcher sent an email to the
Primate Freedom Project stating "you win", and "please don't bother my
family anymore". In another incident at UCLA in June 2007, the Animal Liberation Brigade placed a bomb under the car of a UCLA children's ophthalmologist who experiments on cats and rhesus monkeys; the bomb had a faulty fuse and did not detonate.
In 1997, PETA filmed staff from Huntingdon Life Sciences, showing dogs being mistreated. The employees responsible were dismissed,
with two given community service orders and ordered to pay £250 costs,
the first lab technicians to have been prosecuted for animal cruelty in
the UK. The Stop Huntingdon Animal Cruelty
campaign used tactics ranging from non-violent protest to the alleged
firebombing of houses owned by executives associated with HLS's clients
and investors. The Southern Poverty Law Center, which monitors US domestic extremism, has described SHAC's modus operandi
as "frankly terroristic tactics similar to those of anti-abortion
extremists," and in 2005 an official with the FBI's counter-terrorism
division referred to SHAC's activities in the United States as domestic
terrorist threats.
13 members of SHAC were jailed for between 15 months and eleven years
on charges of conspiracy to blackmail or harm HLS and its suppliers.
These attacks—as well as similar incidents that caused the Southern Poverty Law Center
to declare in 2002 that the animal rights movement had "clearly taken a
turn toward the more extreme"—prompted the US government to pass the Animal Enterprise Terrorism Act and the UK government to add the offense of "Intimidation of persons connected with animal research organisation" to the Serious Organised Crime and Police Act 2005. Such legislation and the arrest and imprisonment of activists may have decreased the incidence of attacks.
Scientific criticism
Systematic reviews have pointed out that animal testing often fails to accurately mirror outcomes in humans.
For instance, a 2013 review noted that some 100 vaccines have been
shown to prevent HIV in animals, yet none of them have worked on humans. Effects seen in animals may not be replicated in humans, and vice versa. Many corticosteroids cause birth defects in animals, but not in humans. Conversely, thalidomide causes serious birth defects in humans, but not in animals. A 2004 paper concluded that much animal research is wasted because systemic reviews are not used, and due to poor methodology.
A 2006 review found multiple studies where there were promising results
for new drugs in animals, but human clinical studies did not show the
same results. The researchers suggested that this might be due to
researcher bias, or simply because animal models do not accurately
reflect human biology. Lack of meta-reviews may be partially to blame. Poor methodology is an issue in many studies. A 2009 review noted that many animal experiments did not use blinded experiments,
a key element of many scientific studies in which researchers are not
told about the part of the study they are working on to reduce bias.
Alternatives to animal testing
Most scientists and governments state that animal testing should
cause as little suffering to animals as possible, and that animal tests
should only be performed where necessary. The "Three Rs" are guiding principles
for the use of animals in research in most countries. Whilst
replacement of animals, i.e. alternatives to animal testing, is one of
the principles, their scope is much broader. Although such principles have been welcomed as a step forwards by some animal welfare groups, they have also been criticized as both outdated by current research, and of little practical effect in improving animal welfare.
The scientists and engineers at Harvard's Wyss Institute
have created "organs-on-a-chip", including the "lung-on-a-chip" and
"gut-on-a-chip". Researchers at cellasys in Germany developed a
"skin-on-a-chip".
These tiny devices contain human cells in a 3-dimensional system that
mimics human organs. The chips can be used instead of animals in in vitro disease research, drug testing, and toxicity testing. Researchers have also begun using 3-D bioprinters to create human tissues for in vitro testing.
Another non-animal research method is in silico
or computer simulation and mathematical modeling which seeks to
investigate and ultimately predict toxicity and drug affects in humans
without using animals. This is done by investigating test compounds on a
molecular level using recent advances in technological capabilities
with the ultimate goal of creating treatments unique to each patient.
Microdosing
is another alternative to the use of animals in experimentation.
Microdosing is a process whereby volunteers are administered a small
dose of a test compound allowing researchers to investigate its
pharmacological affects without harming the volunteers. Microdosing can
replace the use of animals in pre-clinical drug screening and can reduce
the number of animals used in safety and toxicity testing.
Simulators and computer programs have also replaced the use of animals in dissection, teaching and training exercises.
Official bodies such as the European Centre for the Validation of Alternative Test Methods of the European Commission, the Interagency Coordinating Committee for the Validation of Alternative Methods in the US, ZEBET in Germany, and the Japanese Center for the Validation of Alternative Methods
(among others) also promote and disseminate the 3Rs. These bodies are
mainly driven by responding to regulatory requirements, such as
supporting the cosmetics testing ban in the EU by validating alternative
methods.
The European Partnership for Alternative Approaches to Animal
Testing serves as a liaison between the European Commission and
industries. The European Consensus Platform for Alternatives coordinates efforts amongst EU member states.
Academic centers also investigate alternatives, including the Center for Alternatives to Animal Testing at the Johns Hopkins University and the NC3Rs in the UK.
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