COVID-19 vaccine effectiveness in preventing hospitalization drops among oldest Americans, CDC analysis finds

The effectiveness of the COVID-19 vaccines against hospitalization appears to drop over time among adults over 75, although it still remained above 80% at the end of July, according to an analysis released by the Centers for Disease Control and Prevention.

The new data was presented Monday to the CDC's independent panel of vaccine experts, who met to discuss federal plans for a potential booster dose of the COVID-19 vaccine next month. The agency's finding is the latest to suggest protection against severe disease may be starting to wane among the most vulnerable Americans vaccinated earliest in the pandemic, as the country battles a record wave of infections fueled by the Delta variant. But the agency also conceded that drawing conclusions about the amount of time vaccines protect older or more vulnerable people from hospitalization would not be easy.