Misinformation related to vaccination and immunization circulates in mass media and social media. Intentional spreading of false information and conspiracy theories have also been propagated by the general public and celebrities. Misinformation related to vaccination fuels vaccine hesitancy and thereby results in disease outbreaks. Although opposition to vaccination has existed for centuries, the internet and social media has recently facilitated the spread of vaccine-related misinformation. Unsubstantiated safety concerns related to vaccines are often presented as scientific information on the internet.
Extent
A survey by the Royal Society of Public Health found that 50% of the parents of children under age 5 regularly encountered misinformation related to vaccination on social media. On Twitter, bots were found to spread misinformation related to vaccine safety. Bots masquerade as legitimate users, thereby creating false equivalency that there are nearly equal number of individuals on both sides of the debate. The accounts created by bots also use compelling stories related to anti-vaccination as clickbait to drive up their revenue and expose users to malware.
An analysis reveals that anti-vaccine community absorbs individuals who were previously interested in alternative medicine or conspiracy theories. Another study showed that a predisposition to believe in conspiracy theories was found to negatively predict the intention of individuals to be vaccinated.
Spreading vaccine misinformation can lead to financial rewards where posts on social media can be monetized by asking for donations or fundraising for anti-vaccination causes.
List of popular misinformation
The World Health Organization has classified vaccine related misinformation into five topic areas. These are: threat of disease (vaccine preventable diseases are harmless), trust (questioning the trustworthiness of healthcare authorities who administer vaccines), alternative methods (such as alternative medicine to replace vaccination), effectiveness (vaccines do not work) and safety (vaccines have more risks than benefits).
Vaccination causes idiopathic illnesses
- Vaccines cause autism: The established scientific consensus is that there is no link between vaccines and autism. No ingredients in vaccines, including thiomersal, have been found to cause autism.
- Vaccines can cause the same disease that one is vaccinated against: A vaccine causing complete disease is extremely unlikely. In traditional vaccines, the virus is attenuated (weakened) and thus it is not possible to contract the disease, while in newer technologies like mRNA vaccines the vaccine does not contain the virus at all.
- Vaccines cause harmful side effects and even death: Vaccines are very safe. Most adverse events after vaccination are mild and temporary, such as sore throat or mild fever, which can be controlled by taking paracetamol after vaccination.
Alternative remedies to vaccination
Responding to misinformation, some may resort to complementary or alternative medicine as an alternative to vaccination. Those who believe in this narrative view vaccines as 'toxic and adulterating' while seeing alternative 'natural' methods as safe and effective. Some of the misinformation circulating around alternate remedies for vaccination include:
- Eating yoghurt cures human papillomavirus: Eating any natural product does not prevent or cure HPV.
- Homeopathy can be used as an alternative to protect against measles: Homeopathy has been shown to be ineffective against preventing measles.
Vaccination as genocide
Misinformation that forced vaccination could be used to "depopulate" the earth circulated in 2011 by misquoting Bill Gates. Vaccines have falsely been claimed to intervene with the genetic material and alter human DNA.
Vaccine components contain forbidden additives
Anti-vaxxers emphasize that the components in vaccines such as thiomersal and aluminum are capable for causing health hazards. Thiomersal is a harmless component in vaccines which is used to maintain its sterility, and there are no known adverse effects due to it. Aluminium is included in the vaccine as an adjuvant, and it has low toxicity even in large amounts. Formaldehyde included in some vaccines is in negligibly low quantities and it is harmless. Narratives that COVID-19 vaccines contain haram products were circulated in Muslim communities.
Vaccines are part of a governmental/pharmaceutical conspiracy
The Big Pharma conspiracy theory, that pharmaceutical companies operate for sinister purposes and against the public good, has been used in the context of vaccination.
Vaccine preventable diseases are harmless
There is a common misconception that vaccine-preventable diseases such as measles are harmless. However, measles remains a serious disease, and can cause severe complications or even death. Vaccination is the only way to protect against measles.
Personal anecdotes about harmed individuals
Personal anecdotes and sometimes false stories are circulated about vaccination. Misinformation has spread claiming that people died due to COVID-19 vaccination.
Vaccine preventable diseases have been eradicated
Vaccination has enabled the reduction of most vaccine-preventable diseases (e.g. Polio has been eradicated in every country except Afghanistan and Pakistan). However, some are still prevalent and even cause epidemics in some parts of the world. If the affected population is not protected by vaccination, the disease can quickly spread from country to country. Vaccines do not only protect the individual, but also lead to herd immunity if a sufficient number of people in the population have taken the vaccine.
Other conspiracy theories
Other conspiracy theories circulated on social media have included the false notion that polio is not a real disease and that the symptoms are actually due to DDT poisoning, and NASA is releasing balloons filled with chemicals that produce polio-like symptoms. A video shared more than 8,300 times on Facebook falsely claimed that a microchip planted in COVID-19 vaccination syringes "would give officials information on who has and has not been vaccinated" (COVID vaccines do not contain microchips).
Impact
Fueled by misinformation, anti-vaccination activism is on the rise on social media and in many countries. Research has shown that viewing a website containing vaccine misinformation for 5–10 minutes decreases a person's intention to vaccinate. A 2020 study found that "large proportions of the content about vaccines on popular social media sites are anti-vaccination messages." It further found that there is a significant relationship between joining vaccine hesitant groups on social media and openly casting doubts in public about vaccine safety, as well a substantial relationship between foreign disinformation campaigns and declining vaccination coverage.
In 2003, rumors about polio vaccines intensified vaccine hesitancy in Nigeria and led to a five-fold increase in the number of polio cases in the country over three years. A 2021 study found that misinformation about COVID-19 vaccines on social media "induced a decline in intent [to vaccinate] of 6.2 percentage points in the [United Kingdom] and 6.4 percentage points in the [United States] among those who said they would definitely accept a vaccine".
Measures against misinformation
Several governmental agencies, such as the Centers for Disease Control (CDC) in the United States and National Health Service (NHS) in the United Kingdom have dedicated webpages for addressing vaccine related misinformation. Pinterest was one of the first social media platforms to surface only trustworthy information from reliable sources on their vaccine related searches back in 2019. In 2020, Facebook announced that it would no longer allow anti-vaccination advertisements on its platform. Facebook also said it would elevate posts from the World Health Organization and UNICEF in order to increase immunization rates through public health campaigns. Twitter announced that it would put a warning label on tweets containing disputed or unsubstantiated rumors about vaccination and require users to remove tweets that spread false information about vaccines. TikTok announced that it would start directing people to official health sources when they search for vaccine related information. By December 2020, YouTube had removed more than 700,000 videos containing misinformation related to COVID-19.
Research shows that science communicators should directly counter misinformation because of its negative influence on silent audience who are observing the vaccine debate, but not engaging in it. The refutations to vaccine related misinformation should be straightforward in order to avoid emphasising misinformation. It is useful to pair scientific evidence with stories that connect to the belief and value system of the audience.
While social media companies have taken recent steps to reduce the presence of vaccine misinformation on their platforms, misinformed users and their social groups remain. After repeated exposure, these individuals now hold misinformed mental models of the function, risk, and purpose of vaccines. The longer an individual holds misinformation, the more staunchly rooted it becomes in their mental model, making its correction and retraction all the more difficult. Over time, these models may become integral to a vaccine hesitant individual's worldview. People are likely to filter any new information they receive to fit their preexisting worldview – corrective vaccine facts are no exception to this motivated reasoning. Thus, by the time vaccine hesitant individuals arrive at the doctor's office, healthcare workers face an uphill battle. If they seek to change minds and maintain herd immunity against preventable diseases, they must do more than simply present facts about vaccines. Providers need communication strategies that effectively change minds and behavior.
Given the complexity of this problem, effective evidence-based strategies have yet to be identified. Interventions for parents/caregivers who make health decisions for their children are vital. In the United States, the CDC recommends at least 15 vaccinations during the first 18 years of life, given parental consent. This set includes the measles, mumps, and rubella (MMR) vaccine – the central immunization of concern for misinformed parents. Debunked research and celebrity anecdotes that falsely linked the MMR vaccine to autism still have a strong hold on parental behaviors In 15 states, MMR vaccination rates are below 90%. The necessity to counteract misinformation among parents is clear, but the pathway forward is not – researchers are still looking for answers.
Although many wish to provide families with as much corrective information as possible, this often has unintended consequences. One study in 2013 tested four separate interventions to correct MMR vaccine misinformation and promote parental behavioral change: (1) Provide information explaining lack of evidence that MMR causes autism. (2) Present textual information about the dangers of measles, mumps, and rubella. (3) Show images of children with measles, mumps and rubella. (4) Provide a dramatic written narrative about an infant who became deathly ill from measles. Before and after each intervention, researchers measured parents' belief in the vaccine/autism misperception, their intent to vaccinate future children, and their general risk perception of the vaccine. They found that none of the interventions increased parental intent to vaccinate.
Instead, the first intervention (1) reduced misperceptions about autism, but still decreased parents' intent to vaccinate future children. Notably, this effect was significant among parents who were already the most vaccine-hesitant. Nyhan et al. conclude that corrective information may backfire. Motivated reasoning could be the mechanism behind this finding – no matter how many facts are provided, parents still sift through them to selectively find those that support their worldview. While the corrective information did have an effect on a specific belief, ultimately vaccine-hesitant parents used this additional information to strengthen their original behavioral intent. Interventions three (3) and four (4) increased the vaccine/autism misperception and increased belief in serious vaccine side effects, respectively. The authors attribute this result to a potential danger priming effect – when pushed into a fearful state, parents misattribute this fear to the vaccine itself, rather than the diseases it prevents. In all cases, the facts included had little, if not counterproductive effect on future behaviors.
This work has important implications for future research. First, the study's findings revealed a disparity between beliefs and intentions – even as specific misperceptions are corrected, behavior may not change. Since reaching herd immunity for preventable diseases requires promoting a behavior – vaccination – it is important for future research to measure behavioral intent, rather than just beliefs. Second, it is imperative for all health messaging to be tested before its widespread use. We do not necessarily know the behavioral impacts of communication interventions – they may have unintended consequences on different groups. In the case of correcting vaccine misinformation and changing vaccination behaviors, much more research is still needed to identify effective communication strategies.
