Drop in COVID-19 vaccine efficacy against Delta seen in U.S. nursing homes

The effectiveness of COVID-19 vaccines for people in American nursing homes and long-term care facilities, where residents are often elderly and frail, has dropped since the Delta variant became dominant in the United States, government researchers said on Wednesday.

Despite this decline, the vaccines are still highly effective at preventing illness severe enough to require hospitalization, according to research published in the U.S. Centers for Disease Control and Prevention's (CDC) Morbidity and Mortality Weekly Report. The spread of the highly infectious Delta variant, which according to CDC data accounted last month for more than 80% of new U.S. infections, has complicated efforts to combat the pandemic in the United States and globally.