Covid-19: Vaccines prevented illness from latest variants, says CDC

Pfizer Inc/BioNTech SE's and Moderna's updated bivalent Covid-19 vaccines helped prevent symptomatic infections from the XBB-related subvariants of Omicron, according to an analysis from the U.SCenters for Disease Control and Prevention (CDC) released on Wednesday.

The analysis found that the updated vaccine, which targets the BA.4 and BA.5 Omicron variants and the original virus strain, helped prevent illness in people who had previously received two to four doses of the original Covid-19 vaccine, CDC said.

The analysis looked at cases from Dec. 1 until Jan. 13, a time period in which US circulation of XBB and XBB.1.5 increased. The subvariants are descendants of Omicron, the most contagious variant of the virus causing Covid-19.

The CDC said the updated vaccine worked similarly against BA.5-related infections and XBB/XBB.1.5-related infections. It was 52% effective at preventing infections against BA.5 and 48% against XBB/XBB.1.5 among those aged 18-49. Effectiveness fell to 37% against BA.5 and 43% against XBB/XBB.1.5 among those aged 65 years and older.