American Journal of Public Health study examines political differences in perceptions of vaccine safety and effectiveness

Vaccine perceptions can influence acceptance and uptake. Dr. Dror Walter, with the Department of Communication at Georgia State University in Atlanta, and colleagues examined these perceptions using data from a national probability sample of 1,763 US adults surveyed in November 2024. The study was published online in American Journal of Public Health on September 10, 2026.

“Previous research examining associations with vaccine hesitancy has primarily measured perceptions of science and scientists in terms of trust. However, analyses of contemporary arguments on vaccine hesitancy suggest that resistance extends beyond mistrust or doubts about scientists’ competence,” says Dr. Walter.

Notably, respondents rated the MMR vaccine as the safest and most effective, while the COVID-19 vaccine received the lowest ratings for both safety and effectiveness. Republicans generally reported less favorable perceptions of vaccine safety and effectiveness than Democrats, particularly for the COVID-19 vaccine. The findings showed that positive views of science and scientists were associated with higher perceived safety and effectiveness of the MMR, flu, and COVID-19 vaccines.

Explaining the value of this approach, Dr. Walter says, “Our analysis shows that perceiving scientists as unbiased mattered more in Republicans’ assessments of the COVID-19 vaccine’s effectiveness but less so (compared with Democrats) in the case of the MMR’s effectiveness. This difference is likely the result of attacks on the integrity of scientists during the COVID-19 pandemic from the right, as opposed to prepandemic concerns about the MMR vaccine from the left.”

Perceiving science as beneficial was the factor most consistently associated with positive vaccine evaluations across all three vaccines. This pattern suggests that communication emphasizing the tangible benefits of science and vaccines may be particularly effective, especially when tailored to audience concerns and political context.

Dr. Walter and colleagues conclude that understanding vaccine perceptions may benefit from examining both political affiliation and perceptions of science and scientists. This may offer practical insights for addressing vaccine concerns by guiding tailored communication strategies.