CDC COVID-19 vaccine study won't be published

U.S. health officials have stopped the publication of a study on the COVID-19 vaccine's effectiveness in preventing hospitalizations.

A spokesman for the Department of Health and Human Services confirmed the decision on Wednesday, citing concerns about the study's methodology.

The research was set to appear in the CDC's Morbidity and Mortality Weekly Report.

HHS officials argue that factors like prior infection and behavior can affect the results of such studies.

But experts in the field say the methodology is sound and essential for real-time vaccine effectiveness estimates.