New CDC data say vaccine booster effectiveness wanes sharply in months after dose

The Centers for Disease Control and Prevention has released data showing that effectiveness of the COVID-19 vaccine booster wanes markedly in the months following that shot, though the agency still says getting the booster shot is important for fighting against the virus.

The agency said Friday that studies showed effectiveness against COVID emergency-department and urgent-care incidents was "87% and 91%, respectively, during the two months after a third dose" of the booster,” but that it decreased to 66% and 78% by the fourth month after a third dose.

The CDC said that "protection against hospitalizations exceeded that against ED/UC visits" with the shot.

The agency is still telling Americans to get the booster if they are OK to do so. 

"All eligible persons should remain up to date with recommended COVID-19 vaccinations to best protect against COVID-19–associated hospitalizations and ED/UC visits," CDC officials said.