Annenberg study finds social media usage linked to misinformation about vaccines

People who get their news from social media are more likely to be misinformed about vaccines than those who gain their information from traditional media sources, according to a study released by Penn’s Annenberg Public Policy Center on Friday.

Belief in misinformation was linked to patterns of media consumption, the report concluded, as respondents who were exposed to information about vaccines on social media were more likely to become more misinformed. The reverse was true for those who attained their information from traditional media outlets, who were more likely to become better-informed. 

Overall, 19% of respondents incorrectly responded that it was better to develop immunity by getting the disease than by becoming vaccinated, and 15% thought that vaccines are full of toxins.

Researchers called the findings of the survey of almost 2,500 adults “worrying.” Up to 20% of respondents were at least somewhat misinformed about vaccines. A similar study was conducted in the spring of 2019. The Harvard Kennedy School Misinformation Review reported that between the two surveys, 19% of the respondents' level of misinformation changed substantially, and two-thirds of that percentage were more misinformed in the fall than in the spring.

The report’s authors wrote in the Harvard Kennedy School's Misinformation Review that their conclusions are consistent with other research that shows attitudes can change after individuals are exposed briefly to websites that are critical of vaccination. 

The authors suggested that increasing the total amount of pro-vaccine content online and reducing access to anti-vaccine content may be helpful in building trust between medical professionals and patients. They said increasing pro-vaccine content may also increase vaccination rates, which must be kept high in order to maintain the overall immunity of the population to diseases.

The study took place amid the United States' largest outbreak of measles since 1992, with a total of 1,282 cases confirmed in 2019. 

Although no cases of measles were reported at Penn, three students were diagnosed with mumps, and 140 cases of mumps were confirmed at Temple University. The vaccine against measles, known as MMR, also protects against mumps and rubella and came under attack when a study falsely linked it to the development of autism in children in 1998. The study has since been discredited, but 18% of respondents to the Annenberg study believed that vaccines like MMR cause autism.

The Annenberg Public Policy Center’s FactCheck.org website recently debunked a series of online myths about the coronavirus outbreak. Social media posts suggesting conspiracy theories behind the origins and the death toll of the outbreak have gone viral in recent weeks, but Penn has reassured students and staff that the risk to the community remains low. The university’s immunization compliance rate stands at about 99%.