By Carolyn Crist
Jan. 24, 2022 — Booster shots of the Pfizer and Moderna COVID-19 vaccines appear to be highly effective at preventing hospitalizations due to the Omicron variant, according to three new CDC studies published on Friday.
The extra doses were 90% effective at keeping people out of the hospital after infection and 82% effective at preventing emergency department and urgent care visits.
“These reports add more evidence to the importance of being up to date with COVID vaccinations,” Rochelle Walensky, MD, director of the CDC, said Friday during a news briefing by the White House COVID-19 Response Team.
Data from Israel and other countries have suggested that booster shots can prevent severe illness and hospitalization, but it hasn’t been clear until now whether extra doses would have the same effect in the U.S. In the three CDC studies, researchers reviewed millions of cases and tens of thousands of hospitalizations and deaths during the Delta and Omicron waves.
In one study, researchers analyzed hospitalizations and visits to emergency departments and urgent care clinics in 10 states between the end of August 2021 and beginning of January 2022. Vaccine effectiveness against hospitalization with Omicron fell to 57% for those who had received their second dose more than 6 months earlier. A booster shot restored protection to 90%.