Gizem Nisa Demir
23 April 2026•Update: 23 April 2026
- Study, originally scheduled for release in March, delayed and later blocked after internal review raised methodological concerns, officials say
The Centers for Disease Control and Prevention’s (CDC) flagship scientific publication has declined to publish a report that found COVID-19 vaccination significantly reduced hospitalizations, according to multiple media reports on Wednesday.
The study, which reportedly concluded the vaccine cut hospital admissions by nearly half among adults during the winter of 2026, was first scheduled for publication on March 19 but was delayed and later blocked, The Washington Post and CNN reported, citing people familiar with the matter.
Department of Health and Human Services spokesperson Andrew Nixon confirmed the decision on Wednesday.
“Scientific reports are routinely reviewed at multiple levels to ensure they meet the highest standards before publication,” he said, adding that “the manuscript was not accepted for publication.”
According to People, he also pointed to concerns about the “methodological approach estimating vaccine effectiveness.”
Nixon previously said it was “routine for CDC leadership to review and flag concerns about Morbidity and Mortality Weekly Report (MMWR) papers, especially relating to their methodology, leading up to planned publication.”
The Washington Post reported that Acting CDC Director and National Institutes of Health chief Jay Bhattacharya halted the report over methodological concerns. The CDC operates under the Department of Health and Human Services.
The decision comes amid ongoing political debate over vaccines in the US Health and Human Services Secretary Robert F. Kennedy Jr., a longtime vaccine skeptic, has repeatedly called for “transparency” and “informed choice,” saying in a March 2025 Fox News interview:
“We should have transparency. We should have informed choice, and if people don't want it, the government shouldn't force them to do it.”
