A five-year study in Japan has found that vaccine conspiracy beliefs are not a single, uniform phenomenon. Instead, they appear to include at least two distinct forms of thinking: widespread suspicions that governments and pharmaceutical companies conceal information, and far more extreme claims, such as the belief that vaccines contain microchips. The research suggests that these beliefs are shaped differently by people’s relationship with news media and may require different strategies to address.
The study, led by Professor Hitoshi Yamamoto of Rissho University, analyzed longitudinal panel data collected annually from the same participants between 2020 and 2024. By following respondents across five consecutive survey waves, the researchers were able to examine how earlier patterns of media use, media skepticism and perceived media literacy were associated with conspiracy beliefs reported later in the pandemic. The findings were published in Scientific Reports on August 8, 2026, with the research article published on August 3.
Longitudinal research of this kind provides a stronger basis for studying psychological and social change than a single survey conducted at one point in time. Rather than simply identifying whether media skepticism and conspiracy beliefs occur together, the researchers could investigate whether persistent or increasing distrust of mainstream media preceded stronger vaccine-related conspiracy beliefs. This approach does not establish that media skepticism directly causes conspiracy thinking, but it can reveal important temporal relationships that are difficult to detect in cross-sectional studies.
The analysis indicated that institutional distrust-related beliefs were relatively common. These included suspicions that governments, pharmaceutical companies or other powerful organizations were withholding important information about vaccines. Such beliefs may not always involve a completely implausible explanation; instead, they can develop from broader concerns about transparency, commercial influence, political decision-making or the communication of uncertainty during a public-health crisis. The researchers treated this form of conspiratorial thinking as distinct from more extreme claims that conflict sharply with available scientific evidence.
The second category consisted of highly implausible beliefs, including the claim that vaccines contain microchips. Only a small minority of respondents endorsed these ideas. Nevertheless, the researchers caution that their apparent visibility may be amplified in online environments, where emotionally charged, sensational or unusual claims can spread rapidly and attract disproportionate attention. Social media systems that reward engagement may make fringe beliefs seem more widespread than they are in the general population.
A key finding was that institutional distrust-related conspiracy beliefs were more strongly linked to persistent skepticism toward mainstream media. Respondents who consistently questioned the reliability of established news organizations were more likely to express these beliefs, as were those whose skepticism increased over the course of the pandemic. The association suggests that distrust may accumulate over time, particularly when people encounter conflicting information, changing public-health recommendations or messages perceived as politically or commercially motivated.
The researchers also examined subjective media literacy, meaning participants’ own assessment of their ability to evaluate and interpret media information. Feeling confident about identifying misleading content may not necessarily protect people from conspiracy beliefs if that confidence is not matched by effective evaluation skills. In a fragmented information environment, individuals can interpret skepticism itself as evidence of critical thinking, even when they are relying on inaccurate sources or selectively accepting information that confirms pre-existing concerns.
Japan offers a particularly important setting for studying these relationships. Compared with many Western countries, Japan is often characterized by a media environment with lower levels of overt political polarization and broader social consensus around major institutions. The presence of conspiracy-related beliefs in this context indicates that such ideas do not depend exclusively on highly polarized political systems. They may also emerge when people experience uncertainty, perceive institutional communication as inadequate or lose confidence in conventional information channels.
The findings have implications for public-health communication and efforts to counter misinformation. Correcting a false claim with additional facts may be insufficient when the underlying issue is a durable lack of trust in institutions or mainstream journalism. Effective responses may need to address why people doubt official information, explain how scientific recommendations change as evidence develops and make decision-making processes more transparent. The distinction between common institutional suspicions and rare extreme claims could also help communicators design interventions that are proportionate rather than treating all conspiracy beliefs as identical.
“When people think about conspiracy beliefs, attention often focuses on highly extreme claims,” Professor Yamamoto said. “However, our findings suggest that more common forms of conspiracy-related thinking are associated with persistent distrust of social institutions and the mainstream media. Addressing misinformation may therefore require not only correcting factual inaccuracies, but also understanding how distrust develops and persists within contemporary information environments.” By tracking the same individuals through the pandemic, the study provides evidence that the social roots of vaccine conspiracy beliefs may lie less in isolated viral rumors than in longer-term changes in trust, media relationships and perceptions of institutional credibility.
Subject of Research: Vaccine conspiracy beliefs, media skepticism, media use and subjective media literacy in Japan
Article Title: Longitudinal predictors of vaccine conspiracy beliefs: findings from a five-wave panel study in Japan
News Publication Date: August 8, 2026
Web References: https://doi.org/10.1038/s41598-026-57049-5
References: Yamamoto, H., Suzuki, T., Ogawa, Y., & Umetani, R. “Longitudinal predictors of vaccine conspiracy beliefs: findings from a five-wave panel study in Japan.” Scientific Reports, volume 16, Article 23869, published August 3, 2026. DOI: 10.1038/s41598-026-57049-5
Image Credits: Hitoshi Yamamoto at Rissho University
Keywords: vaccine conspiracy beliefs, misinformation, media skepticism, mainstream media, social media, media literacy, institutional trust, COVID-19 pandemic, Japan, public-health communication
