The updated COVID-19 boosters from Pfizer Inc/BioNTech and Moderna helped prevent symptomatic infections against the new XBB-related subvariants, offering new evidence of how the vaccines perform against these fast-spreading strains, U.S. officials said on Wednesday.
“Today we have additional evidence to show that these updated vaccines are protecting people against the latest COVID-19 variants,” Dr. Brendan Jackson, head of the U.S. Centers for Disease Control and Prevention’s COVID-19 response, told reporters in a briefing.
Released last fall, the updated boosters target the BA.4 and BA.5 Omicron variants of the SARS-CoV-2 virus, which are no longer dominant. The now-dominant XBB-related subvariants are derived from the BA.2 version of Omicron.
Lab studies had suggested that vaccine protection was lower against the XBB variants compared with prior variants, raising questions about how well the vaccines worked against these rising strains of the virus, Jackson said.