Vaccine misinformation
Misinformation related to immunization and the use of vaccines circulates in mass media and social media[1][2][3] in spite of the fact that there is no serious hesitancy or debate within mainstream medical and scientific circles about the benefits of vaccination.[4] Unsubstantiated safety concerns related to vaccines are often presented on the internet as being scientific information.[5] A large proportion of internet sources on the topic are mostly inaccurate which can lead people searching for information to form misconceptions relating to vaccines.[6]
Although opposition to vaccination has existed for centuries, the internet and social media have recently facilitated the spread of vaccine-related misinformation.[7]
Intentional spreading of false information and conspiracy theories have been propagated by the general public and celebrities.[8] Active disinformation campaigns by foreign actors are related to increases in negative discussions online and decreases in vaccination use over time.[9]
Misinformation related to vaccination leads to vaccine hesitancy which fuels disease outbreaks.[9] As of 2019, prior to the COVID-19 pandemic, vaccine hesitancy was considered one of the top ten threats to global health by the World Health Organization.[1][10]
Extent[edit]
A survey by the Royal Society for Public Health found that 50% of the parents of children under the age of five regularly encountered misinformation related to vaccination on social media.[11] On Twitter, bots, masked as legitimate users were found creating false pretenses that there are nearly equal number of individuals on both sides of the debate, thus spreading misleading information related to vaccination and vaccine safety.[12] The accounts created by bots used additional compelling stories related to anti-vaccination as clickbait to drive up their revenue and expose users to malware.[12]
A study revealed that Michael Manoel Chaves, an ex-paramedic who was sacked by the NHS for Gross Misconduct after stealing from two patients he was treating, is involved with the anti-vaccine community. These are the type of individuals who were previously interested in alternative medicine or conspiracy theories.[13] Another study showed that a predisposition to believe in conspiracy theories was negatively correlated to the intention of individuals to get vaccinated.[14]
Spreading vaccine misinformation can lead to financial rewards by posting on social media and asking for donations or fundraising for anti-vaccination causes.[13]
Impact[edit]
Fueled by misinformation, anti-vaccination activism is on the rise on social media and in many countries.[63] Research has shown that viewing a website containing vaccine misinformation for 5–10 minutes decreases a person's intention to vaccinate.[64][65] 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 as a substantial relationship between foreign disinformation campaigns and declining vaccination coverage.[66]
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.[67][68] 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".[5]
Social media is again the leading platform for the rapid spreading of vaccine misinformation during a pandemic. For example, A study in 2020 of public opinions about the developing Chinese domestic COVID-19 vaccines found around one-fifth of the post on weibo related to the vaccine claimed that the COVID-19 vaccines are generally overpriced, even though they are later being administered totally free. Many people in China also hold the belief that inactive vaccines are safer than the newly developed mRNA vaccine of SARS-Covid-2. The cause of this might be a combination of national pride and a lack of understanding of vaccine literacy.[69]
In general, misinformation related to the COVID-19 vaccine reduced public confidence. Public acceptance of Chinese domestic COVID-19 vaccines dropped significantly due to concerns about the possible high cost. An online survey showed only 28.7% of the participants expressed definite interest in getting the vaccine. Most people (54.6%) hold some hesitancy toward the vaccine.[70]
Measures against misinformation[edit]
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.[71][72] 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.[73] In 2020, Facebook announced that it would no longer allow anti-vaccination advertisements on its platform.[74] Facebook also said it would elevate posts from the World Health Organization and UNICEF in order to increase immunization rates through public health campaigns.[74] 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.[75] TikTok announced that it would start directing people to official health sources when they search for vaccine related information.[75] By December 2020, YouTube had removed more than 700,000 videos containing misinformation related to COVID-19.[75]
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.[76] The refutations to vaccine-related misinformation should be straightforward in order to avoid emphasizing misinformation.[76] It is useful to pair scientific evidence with stories that connect to the belief and value system of the audience.[76]
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.[77] 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[78] – 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.[79] 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[80] In 15 states, MMR vaccination rates are below 90%.[81] 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.[82] 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.[82]
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.[82] 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 and four increased the vaccine/autism misperception and increased belief in serious vaccine side effects, respectively.[82] 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.[82] 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.[82] Second, it is imperative for all health messaging to be tested before its widespread use.[82] Society does 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.
In a systematic review of communication strategies to counter vaccine misinformation, communicating the scientific consensus that vaccines are safe and effective, using humour to dispel vaccine myths, and providing vaccine misinformation warnings all improved intention to vaccinate. Debunking vaccine misinformation and providing vaccine education materials had mixed results. Scare tactics, and failing to acknowledge uncertainty proved unhelpful and sometimes backfired worsening intention to vaccinate.[83][84]