NEW YORK — A study examining the effectiveness of COVID-19 vaccines, which was previously blocked from publication in a leading U.S. public health journal, has been published in a peer-reviewed medical journal, bringing renewed attention to a dispute over scientific review standards at federal health agencies.
The study appeared on Tuesday in JAMA Network Open after it was not accepted for publication in the U.S. Centers for Disease Control and Prevention’s Morbidity and Mortality Weekly Report (MMWR), according to the study’s authors and federal health officials. The research assessed the effectiveness of updated COVID-19 vaccines during the 2024–25 respiratory virus season.
Researchers reported that vaccination was about 55% effective in preventing COVID-19-associated hospitalizations and reduced emergency department and urgent care visits by about 50%. The findings were broadly consistent with earlier studies showing protection against severe illness, according to the published paper and accompanying reports.
The study had been scheduled for publication in MMWR earlier this year but was delayed and later rejected. A spokesperson for the U.S. Department of Health and Human Services (HHS), which oversees the CDC, said in April that officials had concerns about the study’s “methodological approach estimating vaccine effectiveness.”
The research used a “test-negative design,” a method commonly employed in vaccine effectiveness studies that compares vaccination rates among patients who test positive for a disease with those who have similar symptoms but test negative. Public health researchers have said the approach is widely used and provides timely estimates of vaccine performance, while some officials questioned whether the method could introduce bias.
“It is critical that we continue to characterize and publish estimates of vaccine effectiveness in populations with changing immunity against evolving viral strains,” biostatistician Natalie Dean of Emory University wrote in a commentary accompanying the study’s publication.
The decision to withhold the study from MMWR drew scrutiny because the paper had already undergone internal scientific review, according to current and former CDC officials cited by U.S. media outlets. CDC Chief Science Officer Althea Grant-Lenzy said concerns raised by agency leadership required additional review before publication could proceed.
The publication comes amid broader debates over vaccine research and scientific communication within federal health agencies under the administration of President Donald Trump and Health Secretary Robert F. Kennedy Jr.. HHS has maintained that scientific reports are routinely reviewed to ensure they meet publication standards.
As of Thursday, the study remained publicly available through JAMA Network Open, and federal officials had not announced any change in their assessment of the methodology that led to the original publication decision.
