CDC Cancels Publication of Study Findings Showing COVID-19 Vaccine’s Efficacy

According to a report today in The Washington Post, Centers for Disease Control and Prevention (CDC) Acting Director Jay Bhattacharya, MD, cancelled the publication of a study on the efficacy of COVID-19 vaccines in the agency’s publication, Morbidity and Mortality Weekly Report (MMWR), back in March.¹

The study results found that vaccination cut the likelihood of emergency visits due to COVID-19 by 50% and hospitalizations by 55%, according to a report in The New York Times.² This is an unusual step to remove the potential publication of such a study, especially this far into the process, according to sources in the report. Bhattacharya also met with the study authors previously, and there was no discussion around changing the study.²

“I’ve never seen a case where an article in the MMWR that got to that stage was not published,” Michael Iademarco, MD, who led the publication for several years and was quoted in The New York Times, said.²

Back in February, Bhattacharya was named acting director of the CDC, replacing the previous acting director of the CDC, Jim O’Neill.

In 2020, Bhattacharya was a coauthor of the Great Barrington Declaration, which advocated for the barring of pandemic response lockdown policies and resumption of in-person professional and recreational activities for younger, low-risk persons.

This publication cancellation is a continuing pattern with the current leadership at the health agencies as they continue to reduce access to and data about vaccines. One of the biggest changes to vaccine policy has been US Department of Health and Human Services Secretary Robert F. Kennedy Jr’s changes to the members of the Advisory Committee on Immunization Practices (ACIP). The committee meets to discuss vaccine data and potential policies about immunizations. Kennedy completely replaced the previous ACIP members with individuals who share his vaccine views.

As this is an evolving story, check back for further updates.

References
1. Sun LH. CDC won’t publish report showing COVID shots cut likelihood of hospital visits. Washington Post. April 22, 2026. Accessed April 22, 2026. https://www.washingtonpost.com/health/2026/04/22/covid-vaccine-report-blocked-cdc-mmwr/

2.Mandavilli A. The C.D.C. canceled the publication of a study showing the benefits of COVID vaccines. New York Times. April 22, 2026. Accessed April 22, 2026. https://www.nytimes.com/live/2026/04/22/us/trump-news-updates#section-640670104