The Food and Drug Administration has prevented publication of multiple government-funded safety studies on widely used COVID-19 vaccines and the shingles vaccine Shingrix, prompting concern from independent scientists and public health experts.
What happened
The Department of Health and Human Services, which oversees the FDA, confirmed that several studies prepared by FDA scientists and external contractors were blocked from publication after reviewers had approved them for journal acceptance or conference submission. The New York Times first reported the action.
According to reporting and agency statements, two COVID-19 vaccine safety papers that had been accepted by medical journals were withdrawn in October 2025 before appearing in print. Separately, the FDA declined to sign off on two safety analyses of Shingrix that were intended for presentation at a drug-safety conference. The studies drew on millions of patient records from sources such as Medicare and large insurance databases.
HHS told reporters the decision was driven by concerns about the studies’ conclusions. But several outside experts say that explanation is unsatisfying and suspect political interference, given changes in agency leadership under HHS Secretary Robert F. Kennedy Jr., who has a history of criticizing vaccines.
Why experts are alarmed
Physicians and researchers unaffiliated with the blocked work say the studies used well-established methods for post-market safety surveillance and that withholding them undermines scientific norms. They emphasize three main worries:
– Transparency and trust: Scientists note that disagreement in research is normally resolved through peer review, editorial commentaries, replication studies and published rebuttals. Withholding results removes that public scientific process and may deepen vaccine hesitancy by giving the appearance of suppression rather than scrutiny.
– Value of large real-world datasets: The suspended COVID analyses examined adverse events among millions of people before and after vaccination using insurance and Medicare databases. Experts say such large, real-world studies complement randomized clinical trials and are important for monitoring vaccine safety across diverse populations.
– Perception of political influence: Some researchers view the timing and nature of the decision as consistent with policy shifts at HHS under its current secretary. They worry that blocking internally favorable safety findings fuels concerns that scientific decisions are being driven by ideology rather than evidence.
Perspectives from specialists
Monica Gandhi, a professor of medicine at the University of California, San Francisco, said she was extremely concerned that well-conducted, peer-reviewed analyses documenting vaccine safety and Shingrix effectiveness were being withheld. She argued that publication would have reassured the public.
William Schaffner, an infectious disease and preventive medicine professor at Vanderbilt University Medical Center, emphasized that no single study is perfect, but that a body of different studies using consistent methods builds consensus. He described the blocked reports as the type of real-life evidence clinicians rely on to counsel patients.
Robert Glatter, an emergency physician and assistant professor of emergency medicine, criticized the decision as both ethically questionable and counterproductive. He said that federal agencies have long urged transparency to maintain public trust and that removing data from view risks damaging that trust.
When, if ever, should publication be delayed?
Experts acknowledge there are legitimate reasons to pause or revise a study before publication — for example, to correct methodological errors, address premature conclusions, or resolve conflicts with stronger evidence. But they say such reviews should be handled openly through the standard scientific channels so readers and other scientists can evaluate the critique.
Public health implications
The blocked studies arrive at a time when vaccine confidence remains fragile in some communities. Researchers warn that suppressing government-funded safety analyses could accelerate erosion of public confidence, especially when amplified through social media.
COVID vaccines are among the most intensively studied medical products in history, with large clinical trials and ongoing post-marketing surveillance consistently showing that benefits outweigh rare risks. Several experts say the new analyses appear to confirm that broader evidence, so removing them from the public domain is unlikely to strengthen science and likely to harm perception.
What experts want
Researchers interviewed said they hope the FDA and HHS will reconsider and allow the studies to undergo the usual peer-review and publication processes. Making the full analyses and methods public, they argue, would allow independent scientists to scrutinize the work, replicate findings, and publish rebuttals if warranted — the normal mechanisms that advance understanding and preserve scientific integrity.
Bottom line
Independent experts say the studies should be released through standard scientific channels. Their concern is less about the specific reports than about preserving transparency and the public’s ability to see how vaccine-safety conclusions are reached. In their view, withholding internally favorable findings risks doing greater damage to public health efforts than any single contested analysis could.
The FDA and HHS have not provided detailed, technical explanations of the concerns cited for blocking publication, and the agencies did not comment beyond the initial statement. Scientists say answering that gap publicly — with clear methodological critiques or corrections if they exist — would be the first step toward resolving the controversy.
