- CDC's acting director blocked a COVID-19 vaccine study earlier this year over methodological concerns, but it has now been published in JAMA Network Open, a leading peer-reviewed medical journal.
- The study indicates that annual COVID-19 boosters provide meaningful protection against hospitalization, even for those with some pre-existing immunity.
- Adults who received the 2025–2026 COVID-19 vaccine were approximately 55% less likely to be hospitalized and 50% less likely to require emergency care compared to those who did not receive it.
- The findings suggest that updated boosters can still provide meaningful additional protection against COVID-19, especially for individuals at higher risk of severe illness.
- The study was originally scheduled for release in the Morbidity and Mortality Weekly Report (MMWR) but was pulled by the CDC under the direction of acting director Jay Bhattacharya.
- Bhattacharya criticized the study's test-negative design, claiming it was inadequate to assess vaccine effectiveness, despite similar methodologies being used in other studies.
- Some public health experts viewed Bhattacharya's withdrawal of the study as political interference in the CDC's scientific work.
A COVID-19 vaccine study that was initially blocked by the CDC's acting director, Jay Bhattacharya, has now been published in JAMA Network Open. The study indicates that annual boosters significantly enhance protection against severe illness, even for those with prior immunity.156
The analysis revealed that adults receiving the 2025-2026 COVID-19 vaccine were approximately 55% less likely to be hospitalized due to COVID-19 and 50% less likely to require emergency care compared to unvaccinated individuals. This suggests that updated boosters provide a crucial additional layer of protection, especially for those at higher risk of severe illness.
Originally scheduled for publication in the CDC's Morbidity and Mortality Weekly Report (MMWR), the study was withdrawn by Bhattacharya over concerns regarding its test-negative design, which compares vaccination status between those who test positive and negative for COVID-19. Critics have labeled this withdrawal as potential political interference in scientific research.789
Despite the initial concerns, the study's authors argue that the test-negative design is a “convenient and efficient method” for evaluating vaccine effectiveness in real-world settings. Public health experts have noted that while the limitations of such studies are acknowledged, they do not significantly undermine the conclusions drawn.
The findings underscore the importance of annual COVID-19 boosters in maintaining public health, particularly as the virus continues to evolve.2
“The COVID-19 vaccine study, initially blocked by the CDC's acting director, has been published in JAMA Network Open. It reveals that annual boosters significantly reduce hospitalization rates.”
Gavi, the Vaccine Alliance
Medscape