Covid Boosters Protect Against Latest Omicron Strains in Study

Updated Covid-19 boosters originally designed to protect against early omicron strains continued to reduce rates of illness from new mutants that have since spread rapidly throughout the US.

The shots’ effectiveness against symptomatic infection ranged from 38% to 50% in recent months as the XBB and XBB.1.5 strains became dominant, Centers for Disease Control and Prevention scientists said Wednesday. The boosters helped most in adults from the ages of 18 to 49, according to a study in CDC’s Morbidity and Mortality Weekly Report.

Covid has been continuously evolving to outrun efforts to target it with vaccines, as new mutants arise ...