How Negative is Information About Vaccines on Popular Web Platforms?

Previous research has shown that social media use is associated with vaccine misinformation. Some online platforms have made algorithmic adjustments intended to moderate the conversation in recent years. This raises the question: how accessible is negative content about vaccines today?

A study by investigators from the University of Otago published in Vaccine examined the biases associated with vaccine information online. The team found that while a majority of information is positive, parents researching vaccination online are likely to encounter a substantial minority of negative information.

The study team points out that social media use is ubiquitous and growing in contemporary society, with a reversal unlikely. Therefore, identifying trends on popular web platforms provides important context for what parents are being told about vaccines outside of health care settings.

The investigators searched YouTube, Facebook, and Google using terms a parent might employ. Search terms were gathered using Google Trends in order to replicate what a typical layperson would input.

The study team added descriptive nouns such as “risks” or “benefits” to searches, as well as the names of prominent figures associated with vaccine information. Questions about whether vaccines work or are safe were added as well.

“The search term ‘vaxxed’ was added when it was noted that a lot of videos containing the term vaxxed were coming up in ’related video’ content. Vaxxed is a documentary-style film promoting the claims of the former physician, Andrew Wakefield, who hypothesized the now thoroughly discredited association between the MMR [measles, mumps, and rubella] vaccine and autism,” the study authors wrote.

None of the popular search terms resulted in platforms giving uniformly positive or negative information about vaccines. The majority of videos found on YouTube (75%) and websites generated by Google (80%) were considered “vaccine-positive”.

Half of the Facebook pages generated by popular search terms were “vaccine-negative”, but the majority tended to be “vaccine-skeptical” rather than outright “vaccine-discouraging”.

Out of the 20 most liked Facebook pages about vaccines, 7 were “vaccine-promoting”, 3 were “vaccine-positive”, 7 were “vaccine-skeptical”, and 3 were “vaccine-discouraging”.

Among the 20 vaccine related websites most frequently generated by a Google search, 14 were “vaccine-promoting”, 2 were positive about vaccines, 2 were neutral, 1 was skeptical, and 1 was discouraging.

Out of the 20 most viewed YouTube videos about vaccines, 6 were “vaccine-promoting”, 9 were “vaccine-positive”, 3 were skeptical, and 2 were discouraging.

“Information that was positively disposed towards vaccination often included information on the risks of vaccination or about people who should not have certain vaccinations. Those that were negatively disposed to vaccination often argued that they were not anti-all vaccines, or that they were not against vaccination per se, but were advocating for informed consent, and for more research and information about vaccine safety,” the study authors explained.

The aim of the study was not to qualify whether all information was scientifically credible, but to investigate bias.

Pointing to early research, the investigators note that negative information used to be much more readily accessible. However, there is still a substantial amount of negative information available, particularly on Facebook. At a time when some US states are seeing a rise in philosophical vaccine exemptions, it is important that risks are contextualized by the overwhelming benefits of vaccination.