Overview
- The Department of Health and Human Services confirmed that the CDC’s Morbidity and Mortality Weekly Report declined a CDC manuscript after editors cited problems with how it estimated vaccine effectiveness.
- The blocked study, based on CDC-led VISION network data from last fall and winter, reported about 50% fewer emergency visits and 55% fewer hospitalizations among healthy vaccinated adults compared with unvaccinated peers.
- Acting CDC director Jay Bhattacharya objected to the study’s test-negative design, a common observational method that compares vaccination rates among patients who test positive versus negative for the virus.
- HHS officials said factors such as prior infection, personal behavior, and who seeks medical care could skew results, while former CDC scientists countered that the design is standard and that stopping an MMWR paper after full scientific clearance is highly unusual.
- The authors declined to change the design after meeting with leadership, and the decision lands as Health Secretary Robert F. Kennedy Jr.’s vaccine policy shifts face congressional scrutiny and as clinicians who rely on MMWR lose timely data that can guide care.