June 23, 2026
Alicia Devine/Imagn Images via Reuters Connect
A study that was blocked from being run in a CDC report was published Tuesday by a major medical journal.
The COVID-19 vaccine cut emergency department visits and hospitalizations in half over the winter, a study found, but the head of the Centers for Disease Control and Prevention kept those findings from being published by the agency in March.
On Tuesday, the research was published in JAMA Network Open, a well-established medical journal.
In April, the Washington Post reported that acting CDC chief Jay Bhattacharya had objected to the design of the original study that was supposed to be published in the CDC's Mortality and Morbidity Report on March 19. The study already had been approved by CDC research teams, according to KFF.
The study published by JAMA followed the same design as the original one, revealing that being vaccinated against COVID offered robust protection last winter against severe forms of the illness, regardless of previous immunity.
"These findings suggest that adults can reduce their likelihood of severe COVID-19–associated outcomes by obtaining a 2025-2026 COVID-19 vaccination," the researchers wrote.
Some public health experts bristled when the original findings were withheld and saw it as evidence of the Trump administration thwarting evidence-based science. Health and Human Services Secretary Robert F. Kennedy Jr. has for years expressed skepticism about vaccines. In 2021, Kennedy falsely claimed the COVID-19 vaccine was "the deadliest vaccine ever made."
In an op-ed published by the Washington Post on April 30, Bhattacharya defended his move to keep the original study out of the CDC report, saying it relied on a test-negative design that has "well-known limitations."
Test-negative methodology is the most common way of examining the effectiveness of vaccines. The research used data from patients who had sought treatment for COVID-like symptoms between September and December last year. People who tested positive for COVID were identified as "cases," and people who tested negative as "controls," enabling the researchers to compare vaccination status.
This type of test design, despite limitations, "remains an important and practical approach while other options continue to mature," Natalie Dean, a biostatistics and bioinformatics researcher at Emory Rollins School of Public Health in Atlanta, wrote in a commentary accompanying the study's publication.
"Science was never the issue," Dr. Michelle Barron, one of the study's authors and senior medical director of infection prevention and control for UCHealth, a nonprofit health system in Colorado, told the Washington Post. "Certainly it was within (the CDC's) purview to keep it out, for whatever reason, but it was clearly not for scientific reasons that the study was withheld from publication in the MMWR."
