The study, led by researchers from the Annenberg Public Policy Center at the University of Pennsylvania, was published in the American Journal of Public Health. It was an observational analysis of a probability sample, so its findings identify associations rather than establishing that attitudes toward science caused particular vaccine judgments. The results also apply to the three vaccines and survey period examined and do not directly measure vaccination behavior or changes over time.

Researchers used data collected in November 2024 through the Annenberg Science and Public Health survey. The national probability sample of 1,763 empaneled U.S. adults rated the safety and effectiveness of the measles, mumps and rubella vaccine, the seasonal flu vaccine and the Covid-19 vaccine. Respondents also answered questions about their views of science and scientists.

To measure those views, the team used the Factors Assessing Science’s Self-Presentation model, or FASS, introduced by Annenberg researchers in 2023. It considers five aspects: whether scientists are credible, prudent and unbiased, and whether science is beneficial and self-correcting. This allowed the analysis to examine specific attitudes rather than combine them into a single measure of trust in science.

On four-point scales, the MMR vaccine received the highest average ratings for both safety and effectiveness, at 3.54 and 3.63, respectively. The flu vaccine followed with an average safety rating of 3.41 and an effectiveness rating of 3.03. The Covid-19 vaccine had the lowest averages among the three: 2.98 for safety and 2.81 for effectiveness. These figures describe respondents’ perceptions, not estimates of the vaccines’ clinical performance.

Democrats rated the MMR, flu and Covid-19 vaccines as safer and more effective than Republicans did. After the researchers statistically accounted for respondents’ broader perceptions of science and scientists, the partisan differences for MMR and flu were no longer statistically significant. For Covid-19, however, political affiliation remained significantly associated with perceived safety and effectiveness.

One FASS attribute was consistently associated across the results: viewing science as beneficial was associated with believing that all three vaccines were both safe and effective. Other attributes, including scientists’ perceived credibility, prudence and lack of bias, were associated with some vaccine evaluations but not others. For the Covid-19 vaccine, the study’s results suggested that positive perceptions of science and scientists were more strongly associated with vaccine perceptions among Republicans than among Democrats.

The researchers said the vaccines’ different histories may help explain why the pattern varied. They noted that MMR has been widely used for decades, while the Covid-19 vaccine was introduced during an intensely polarized pandemic and became the subject of attacks by political figures and partisan media. They also noted that seasonal flu vaccine effectiveness varies by season, partly because of how well the vaccine matches circulating strains. The study did not directly test these historical or political explanations.

On that basis, the researchers suggested that vaccine communication should account for the particular vaccine, its history, perceived safety and effectiveness, and the political affiliation of the intended audience. For Covid-19, they said communications may need to address concerns about scientific bias and could explain mechanisms through which science identifies and corrects bias. The authors emphasized that further research would be needed to test whether those approaches are effective, and said responsible communication consistent with scientific evidence is important when vaccines become politically polarized.

Subject of Research: A cross-sectional U.S. survey examining associations among political affiliation, perceptions of science, and perceived vaccine safety and effectiveness.

Article Title: Views of science help explain partisan differences over vaccine safety and effectiveness

Article References: Views of science help explain partisan differences over vaccine safety and effectiveness. Original publication (Bibliographic details unavailable.)

Image Credits: AI Generated

DOI: Not provided

Keywords: vaccine perceptions, science communication, partisan differences, MMR vaccine, flu vaccine, Covid-19 vaccine, vaccine safety, vaccine effectiveness, FASS model, survey research, Views, science

The study drew on nationwide survey data collected in 2025, covering children aged 1 to 17 years and their parents, with an additional linked sub-analysis spanning 2023 to 2025. The researchers defined regular parental AI use as consulting generative AI tools for health advice at least a few times per month. Among the 8,282 children and 5,170 parents analyzed, 1,278 children, or 15.4 percent, had parents who were regular AI health-advice users. This figure offers one of the first quantitative snapshots of how deeply chatbot-based health information seeking has penetrated everyday parenting in a developed health system.

To estimate the relationship between AI use and vaccination, the team employed modified Poisson regression, a statistical approach well suited to common binary outcomes such as whether a child received a particular vaccine. The models produced adjusted prevalence ratios, or aPRs, with 95 percent confidence intervals, while accounting for parent-level clustering and a battery of covariates. This clustering adjustment matters because some parents contributed more than one child to the dataset, and ignoring that structure would have artificially narrowed the confidence intervals and inflated the apparent precision of the estimates.

The headline result is a striking asymmetry across vaccines. For age-appropriate measles-rubella vaccination, the adjusted prevalence ratio was 1.02 with a confidence interval of 0.97 to 1.09, meaning the association was statistically indistinguishable from no difference at all. Yet for the three other vaccines examined, the associations were positive and statistically significant. Children of regular AI users had an adjusted vaccination rate of 76.6 percent for mumps compared with 72.7 percent among children of non-users, an aPR of 1.05. For influenza, the gap widened to 56.7 percent versus 49.0 percent, an aPR of 1.16. The largest difference appeared for COVID-19 vaccination, where 40.6 percent of children of AI-using parents were vaccinated compared with 30.9 percent of the rest, yielding an aPR of 1.31 with a confidence interval of 1.19 to 1.45.

Perhaps the most eye-catching finding emerged when the researchers stratified the COVID-19 result by parental age. Among parents younger than 30 years, the association was dramatically amplified, with an adjusted prevalence ratio of 2.58 and a confidence interval of 1.90 to 3.50, and a P value for interaction below 0.001. In practical terms, the youngest parents who regularly consulted AI for health advice had their children vaccinated against COVID-19 at more than two and a half times the rate of their peers who did not use AI, after adjustment. This age gradient suggests that the phenomenon is concentrated among the demographic most comfortable with conversational AI tools, and it hints that generative chatbots may function as a novel information gateway for a generation of parents who came of age alongside smartphones.

The authors did not stop at the cross-sectional snapshot. In a linked sub-analysis covering 2023 to 2025, they tested whether the associations persisted after adjusting for an available 2023 household-level prior vaccination marker and for vaccination attitudes. The associations survived this additional adjustment, which strengthens the case that the relationship is not simply an artifact of pre-existing vaccine-friendly households. Even so, the design remains observational and cross-sectional, and the authors are explicit that these are exploratory associations rather than evidence of causation.

Indeed, the study’s own interpretation is notably cautious. The researchers write that the findings may reflect digital health engagement, health information seeking, socioeconomic differences, or favorable attitudes, rather than vaccine-specific AI advice. In other words, parents who consult chatbots about their children’s health are likely a self-selected group: more digitally literate, more proactive about health information in general, and possibly more trusting of medical recommendations to begin with. The absence of an association with measles-rubella vaccination is consistent with this reading, because MR vaccination in Japan is a long-established routine immunization with near-universal promotion, leaving little room for any information source, AI or otherwise, to move the needle.

The contrast between the MR null result and the positive associations for the other three vaccines is itself informative. Mumps, influenza, and COVID-19 vaccines in Japan occupy a different position in the immunization landscape: they are either voluntary, more recently introduced for children, or subject to more fluctuating public debate. For these vaccines, parental decision-making is more contingent, and information-seeking behavior plausibly plays a larger role. A parent uncertain about whether to get their child a seasonal flu shot or a COVID-19 booster may find that a chatbot conversation supplies the nudge, the reassurance, or the practical details that tip the balance toward vaccination.

The study sits within a rapidly growing literature on AI and vaccine behavior. Prior evaluations have found that large language models generally align with World Health Organization positions on vaccine hesitancy and can counter common vaccination myths, while randomized trials of purpose-built vaccine chatbots have shown meaningful increases in HPV and influenza vaccination uptake. The Japanese findings add an observational, population-level dimension to this evidence base, suggesting that spontaneous, unguided AI use by parents correlates with higher uptake of vaccines where hesitancy or inertia is most common. At the same time, other research has flagged reliability and readability concerns in AI-generated pediatric health advice, underscoring that the quality of chatbot answers varies and that expert oversight remains essential.

For public health practitioners, the implications are twofold. First, generative AI has become a mainstream channel through which a meaningful minority of parents, roughly one in six in this sample, seek child health guidance, and that channel appears to lean toward vaccine-promoting rather than vaccine-skeptical behavior, at least in this Japanese cohort. Second, because the associations are strongest for vaccines where decision-making is most contested and among the youngest parents, health communicators may need to treat AI tools not merely as a risk to be mitigated but as an environment to be engaged. Whether the relationship is causal, and whether AI advice actively drives vaccination or simply marks out an already engaged population, will require longitudinal and interventional designs. Until then, this study stands as an early signal that the chatbot era is quietly reshaping how families navigate childhood immunization.

Subject of Research: Parental generative AI health-advice use and childhood vaccination uptake in Japan

Article Title: Associations between parental generative artificial intelligence health-advice use and child vaccination uptake in Japan: an exploratory cross-sectional study

Article References: Imanishi, Y., Iorini, M., Jwa, S., Sakamoto, M., Wada, I., Tabuchi, T., & Uchida, M. (2026). Associations between parental generative artificial intelligence health-advice use and child vaccination uptake in Japan: an exploratory cross-sectional study. World Journal of Pediatrics. https://doi.org/10.1007/s12519-026-01107-5

Image Credits: AI Generated

DOI: 10.1007/s12519-026-01107-5

Keywords: generative artificial intelligence, child vaccination, vaccine hesitancy, parental health information seeking, COVID-19 vaccine, influenza vaccine, mumps vaccine, measles-rubella vaccine, Japan, cross-sectional study, pediatrics, digital health

The research team set out to move beyond a long-standing limitation in the vaccine hesitancy literature. Previous studies attempting to explain why some people resist vaccination have overwhelmingly measured attitudes toward science and scientists through a single lens: trust. Yet contemporary debates about vaccines, playing out across news media, social platforms, and everyday conversation, suggest that hesitancy is rarely reducible to simple mistrust or doubts about the competence of researchers. People may accept that scientists are skilled while questioning whether science is beneficial, whether scientific institutions are unbiased, whether scientific claims are credible, and whether scientific interventions are prudent. The new study therefore disaggregated perceptions of science and scientists into these distinct dimensions and tested how each related to vaccine evaluations across the political spectrum.

The technical architecture of the analysis rested on the national probability sample, a methodological gold standard that allows findings from roughly 1,763 respondents to be generalized to the adult population of the United States with quantifiable confidence. Fielded in November 2024, the survey captured perceptions of three vaccines that occupy very different positions in American public health history and political discourse: the measles, mumps, and rubella vaccine, a decades-old mainstay of childhood immunization schedules; the seasonal influenza vaccine, renewed annually and broadly familiar to the public; and the COVID-19 vaccine, developed at unprecedented speed during a global emergency and subsequently swept into partisan controversy.

The results painted a consistent hierarchy of public confidence. Respondents rated the MMR vaccine as the safest and most effective of the three, a verdict that aligns with its long track record and its relative insulation from recent partisan battles. The COVID-19 vaccine received the lowest ratings on both dimensions, perceived as neither as safe nor as effective as its older counterparts. The influenza vaccine fell between these poles. This ordering matters because perceived safety and perceived effectiveness are the twin psychological pillars on which vaccine acceptance rests; when either erodes, uptake tends to follow, and the consequences ripple outward through community immunity and disease transmission.

Political affiliation emerged as a powerful organizing variable. Republicans generally reported less favorable perceptions of vaccine safety and effectiveness than Democrats, and the gap widened dramatically for the COVID-19 vaccine, confirming that the politicization of that vaccine during and after the pandemic left a durable imprint on public judgment. The MMR and influenza vaccines, by contrast, showed smaller partisan differences, suggesting that the polarization surrounding COVID-19 immunization is not simply a generalized Republican skepticism of all vaccines but a vaccine-specific phenomenon rooted in the particular political history of the pandemic response.

Perhaps the most illuminating findings concerned the specific dimensions of perceptions of science and scientists. Across all three vaccines, one factor stood out for its consistency: perceiving science as beneficial was the strongest and most reliable correlate of positive vaccine evaluations. Americans who saw science as delivering tangible advantages to society were markedly more likely to rate each vaccine as safe and effective, regardless of party. This pattern held for the MMR vaccine, the flu vaccine, and the COVID-19 vaccine alike, making the perceived benefit of science the single most robust psychological predictor in the entire analysis.

Other dimensions of scientific perception showed more nuanced, politically contingent effects. Perceiving scientists as unbiased mattered more in Republicans’ assessments of the COVID-19 vaccine’s effectiveness, but played a comparatively smaller role among Democrats in evaluations of the MMR vaccine’s effectiveness. Dr. Walter offered a pointed interpretation of this asymmetry, noting that the 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. In other words, when a community has been told repeatedly that scientists cannot be trusted to be impartial, the perceived impartiality of scientists becomes the decisive question for that group, whereas older vaccine controversies rooted in different political traditions activate different concerns.

The study’s framework implies that vaccine communication strategies built solely on appeals to trust may be leaving important levers unused. If resistance extends beyond mistrust or doubts about scientists’ competence, then interventions that address whether science is viewed as beneficial, credible, unbiased, and prudent may reach audiences that trust-based messaging misses. The finding that perceived benefit is the most consistently associated factor suggests that communication emphasizing the concrete, tangible benefits of science and vaccines, from prevented illnesses to protected communities, may be particularly effective, especially when tailored to the specific concerns and political context of the audience being addressed.

Such tailoring is not a matter of partisan pandering but of diagnostic precision. The data indicate that a communication strategy optimized for a Democratic audience evaluating the MMR vaccine may be poorly suited to a Republican audience evaluating the COVID-19 vaccine, because the psychological pathways underlying those judgments differ. For the latter group, evidence and messaging that directly address the integrity and impartiality of the scientific enterprise may carry disproportionate weight. For audiences weighing older vaccines, reinforcing the everyday benefits that science delivers may be the more productive route. The authors conclude that understanding vaccine perceptions benefits from examining both political affiliation and the multidimensional perceptions of science and scientists, an approach that offers practical insights for guiding tailored communication strategies rather than one-size-fits-all campaigns.

The implications extend well beyond the three vaccines studied. As public health authorities confront resurgent measles outbreaks, seasonal influenza burdens, and the ongoing task of maintaining COVID-19 immunization coverage, the study provides an evidence-based map of where public confidence stands and why it varies. It demonstrates that the American public does not hold a single undifferentiated attitude toward science but a bundle of distinct perceptions, each with its own political geography and its own relationship to vaccine judgment. For researchers, the work models a more granular approach to measuring science attitudes. For practitioners, it delivers a clear message: the path to higher vaccine confidence runs through demonstrating the benefits of science, defending the integrity of scientists where it has been called into question, and meeting audiences where their political experiences have shaped what they doubt and what they believe.

Subject of Research: Political affiliation and perceptions of science and scientists in relation to perceived vaccine safety and effectiveness in the United States

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

Article References: American Journal of Public Health study examines political differences in perceptions of vaccine safety and effectiveness. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: vaccine hesitancy, vaccine safety, vaccine effectiveness, political affiliation, perceptions of science, MMR vaccine, COVID-19 vaccine, influenza vaccine, public health, health communication, survey research, American Journal of Public Health