Pfizer says its updated booster, which was designed to target Omicron BA.4 and BA.5, also protects against surging Omicron subvariants like BQ.1.1 and BQ.1.
A month after getting the bivalent booster, adults 55 and over were found to have a nine-fold increase in antibodies against BQ.1.1, Pfizer said in a news release. People who got another dose of the original vaccine showed a two-fold increase in antibodies against BQ1.1.
“Results showed the bivalent vaccine booster elicited a greater rise in neutralizing antibody titers for all tested Omicron sublineages compared to the original vaccine, regardless of prior SARS-CoV-2 infection status,” Pfizer said.
Bivalent boosters contains two strains of vaccine – one to protect against the original COVID-19 virus and another targeting Omicron subvariants. The bivalent booster works best against BA.5, producing a 13-fold increase in antibodies in people older than 55, Pfizer has said.
When the updated booster was developed, BA.5 was the dominant strain of COVID in the United States, but that has changed in recent months.
According to information posted by the U.S. Centers for Disease Control and Protection on Saturday, BA.5 now accounts for about 24% of cases while BQ.1.1 accounts for 24.2% and its cousin BQ.1 for 25%.
Moderna reported on Nov. 14 that its bivalent booster provides protection against BQ.1.1 but not as much as against the BA.5 variant.
Peter Marks, director of the FDA’s vaccine division, said he was encouraged by the findings from Pfizer and Moderna.
“With the increasing prevalence of BQ.1.1 and the amount of travel that will occur starting around Thanksgiving, it will be very important for all those eligible, and particularly older adults, to consider getting the updated vaccine for protection if they have not yet done so,” he said, according to CNBC.
Pfizer: “Pfizer and BioNTech Report New Data on Omicron BA.4/BA.5-Adapted Bivalent”
CDC: “Variant Proportions”