Growing distrust may prime vaccine conspiracy beliefs

Clinical takeaway: When patients raise vaccine conspiracy beliefs, distrust of institutions may be as relevant as the misinformation itself and help explain why those beliefs persist.

Correcting a false vaccine claim assumes that the disagreement is mainly about facts. But facts alone may not change a patient’s mind when the patient already distrusts the institutions behind them.

A five-year study in Japan suggests that this distrust may build before a specific vaccine conspiracy belief appears. People whose skepticism toward mainstream media stayed high or increased during the COVID-19 pandemic later reported stronger vaccine conspiracy beliefs. The model based on media skepticism explained about 35% of the differences in these beliefs, compared with 7% for media use alone. Once skepticism was considered, how often people used mass or social media no longer showed a clear relationship with conspiracy beliefs.

The beliefs most closely related to media skepticism were claims that governments, scientists, and pharmaceutical companies were hiding vaccine harms. These beliefs varied widely across the sample, while extreme claims about microchips, tracking devices, or mind control were endorsed by only a small minority.

The more common clinical challenge may be distrust that does not sound overtly conspiratorial. Patients may question whether health authorities are being honest, pharmaceutical companies can be trusted, or important vaccine risks are being left out.

“When people think about conspiracy beliefs, attention often focuses on highly extreme claims,” said Professor Hitoshi Yamamoto of Rissho University. “However, our findings suggest that more common forms of conspiracy-related thinking are associated with persistent distrust of social institutions and the mainstream media.”

Researchers surveyed the same group once a year from 2020 to 2024. The study started with 2,000 participants, with 600 remaining in the final year when vaccine conspiracy beliefs were measured. Because the media-use measures combined different platforms together, the analysis captures broad media habits rather than specific sources.

The study shows that media distrust was already present before vaccine conspiracy beliefs were measured, but it does not explain what shaped that distrust. Another recent paper examining the connection between lifetime adversity and conspiracy theories offers one possible clue: People who saw the world as more unfair reported stronger conspiracy beliefs and less trust in institutions, suggesting that broader views about fairness may feed into the same loss of confidence seen in the vaccine study.

Together, the findings shift attention from the false claim alone to the distrust surrounding it. Addressing both the misinformation and concerns that institutions are not being transparent may open a more productive vaccine conversation.

Sources: Yamamoto H, et al. (2026 Aug 8) Sci Rep.Longitudinal predictors of vaccine conspiracy beliefs: findings from a five-wave panel study in Japan; Jolley D, et al. (2026 Aug 4) Br J Psychol. The world is an unjust place: The impact of lifetime adversity on belief in conspiracy theories