Updated COVID-19 Vaccines Needed Due to Waning Effectiveness: FDA

The U.S. Food and Drug Administration in White Oak, Md., on July 20, 2020. Sarah Silbiger/Getty Images

Newly formulated COVID-19 vaccines are necessary because the performance of the current slate is slipping over time, U.S. officials said this week.

“There appears to be an inverse relationship between the time since vaccination and vaccine effectiveness, such that bivalent COVID-19 vaccine effectiveness against Omicron sublineages appears to wane over time,” Food and Drug Administration (FDA) officials said.