Overview
- HHS and CDC, which on Wednesday confirmed the MMWR rejection, blocked a CDC-authored paper on vaccine effectiveness after delaying its release in March.
- The study, using CDC’s VISION hospital network data from September to December 2025, estimated about 50% fewer emergency or urgent care visits and 55% fewer hospitalizations for vaccinated healthy adults.
- Leaders objected to the test-negative design, a method that estimates protection by comparing vaccination rates in patients who test positive for COVID-19 with those who test negative for the same symptoms.
- The manuscript had cleared CDC scientific review and was scheduled for the March 19 MMWR, and acting director Jay Bhattacharya met the authors, who declined to change the approach before the journal issued a rejection.
- Former CDC officials called canceling a cleared MMWR paper unusual and warned the move could erode trust, slow guidance clinicians rely on, and intensify political fights over vaccine policy already drawing congressional scrutiny.