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Media Skepticism, Not Just COVID News, Predicted Vaccine Conspiracy Beliefs
In A Nutshell
- A five-year study of 2,000 people in Japan found that distrust of mainstream media, not pandemic-era headlines, was the strongest link to vaccine conspiracy beliefs by 2024.
- Researchers identified two distinct types of belief: common cover-up claims about governments and drug companies, and much rarer, extreme claims like vaccine microchips.
- Once media skepticism was factored in, simply watching less TV or reading fewer newspapers stopped predicting conspiracy beliefs, skepticism itself mattered more than media habits.
- Extreme conspiracy claims were rare in the actual data but may seem more common online because they attract outsized attention and visibility.
One popular explanation for vaccine conspiracy theories is that the pandemic created them; that a flood of confusing headlines and social media posts pushed people toward believing governments and drug companies were hiding the truth. However, distrust in mainstream media was already there when researchers started watching in 2020, and it only grew stronger from there.
A five-wave study published in Scientific Reports suggests the COVID-19 explanation misses something important. Researchers followed the same 2,000 people in Japan for five years, starting in April 2020, and found that people who already distrusted mainstream news early on, and grew even more distrustful as time went on, were the ones most likely to believe vaccines were part of a cover-up by 2024.
This finding carries extra weight because of where it came from. Japan’s major news outlets have traditionally emphasized political neutrality, and the country’s media landscape has been less fragmented along partisan lines than in the United States. That makes it a useful place to study media distrust without the usual noise of partisan echo chambers clouding the picture.
Institutional Distrust and Microchip Myths Are Not the Same Belief
Using an eight-item survey given in the study’s final year, researchers found two separate kinds of vaccine conspiracy belief, not one big blob of “distrust.” The first, which researchers call institutional conspiracy belief, is the idea that governments and drug companies are hiding vaccine dangers or covering up links between vaccines and health problems, like claiming officials are burying evidence that a vaccine causes harm. This one was common and varied a lot from person to person.
A second, rarer category involves far more extreme claims, such as vaccines containing tracking microchips or enabling mind control. Only a small minority endorsed these ideas. Most people, even those skeptical of institutions, rejected the microchip-style narratives outright.
Someone who suspects pharmaceutical companies of hiding side effects is working from a different psychological place than someone convinced vaccines contain tracking devices. Treating both as the same problem risks building public health messages that miss their target.
Media Skepticism Outweighed Media Use as a Predictor
Starting in April 2020, researchers recruited 2,000 participants through an online platform in Japan. Each year through April 2024, they re-surveyed as many original participants as were willing to continue, ending with 600 by the final wave. Participants reported how often they used television, newspapers and social media, how skeptical they felt toward mainstream news, and how confident they were in judging accurate information themselves. The conspiracy belief questions were asked only once, at the end, in 2024.
Age mattered too: younger participants scored higher on both types of belief. But the single strongest factor behind the common, cover-up-style belief was media skepticism, both how distrustful people were at the start and how much more distrustful they became.
Watching less traditional TV and print news was also linked to higher conspiracy beliefs, but that link disappeared once researchers factored in skepticism itself. In other words, it wasn’t really about how much news people consumed. It was about how much they trusted the source in the first place.
Social media use alone did not clearly predict institutional conspiracy beliefs. Some patterns hinted at a possible link to the rarer, extreme beliefs, but researchers described those results as speculative given how few participants held such views.
Extreme Vaccine Claims Are Rare but Loud Online
A common theory about online misinformation holds that social media algorithms trap people in echo chambers, feeding them extreme content until new beliefs take hold. That theory suggests conspiracy beliefs are mostly manufactured by bad information people run into online. Researchers argue instead that this kind of distrust reflects a lasting mindset rather than just a reaction to pandemic news, though they’re careful to note their data can’t fully prove cause and effect. If that reading holds up, fact-checking alone won’t be enough. Health officials correcting misinformation may be talking to people who already don’t trust the messenger, not just the message.
One more result stands out. Extreme conspiracy beliefs were rare in the actual data, yet anyone active on social media knows these claims can seem to be everywhere, showing up in comment sections and viral posts far more often than the underlying numbers would suggest. The researchers noted that highly implausible beliefs may attract outsized visibility online even when few people genuinely hold them. Studies that infer public belief from highly visible online posts may overestimate how common the most extreme views really are.
Vaccine conspiracy theories don’t exist in a vacuum. The widespread version is tied to something older and harder to shake than a single health crisis, and the version that dominates online attention belongs to a much smaller group than the noise suggests.
Disclaimer: This article summarizes findings from a peer-reviewed study and is intended for general informational purposes. It does not constitute medical advice. Readers with questions about vaccines or personal health decisions should consult a qualified healthcare provider.
Paper Notes
Limitations
Researchers acknowledged several limitations. The media-use measures combined multiple platforms into broad totals, which may obscure differences between, say, television news and YouTube. The study focused on media-related factors but noted that trust in science, social norms and group identity, not examined here, likely also shape conspiracy beliefs. Because participants were recruited through an online platform in Japan, results may not generalize to people with different media habits or digital access. Researchers also cautioned that age-related findings may partly reflect which participants chose to remain in the study over its five years, rather than a straightforward effect of age itself.
Funding and Disclosures
This work was supported by JSPS KAKENHI Grant Numbers 21KK0027 and 23K25160. Authors Hitoshi Yamamoto and Takahisa Suzuki are listed as grant recipients. All authors declared no competing interests. Ethical approval was granted by the Ethics Committee of Rissho University across multiple approval numbers spanning the study’s five years. All participants provided informed consent.
Publication Details
Authors: Hitoshi Yamamoto (Rissho University, Tokyo), Takahisa Suzuki (Tsuda University, Tokyo), Yuki Ogawa (Tokyo City University, Kanagawa), and Ryohei Umetani (National Institute of Advanced Industrial Science and Technology, Ibaraki, and Meiji University, Tokyo). Yamamoto and Suzuki contributed equally. | Journal: Scientific Reports | Paper Title: “Longitudinal predictors of vaccine conspiracy beliefs: findings from a five-wave panel study in Japan” | DOI: https://doi.org/10.1038/s41598-026-57049-5 | Published: 2026 (received February 22, 2026; accepted June 4, 2026)
