Pfizer: New booster is more effective

Pfizer and its German vaccine partner said their booster tailored to the latest omicron variants raised more antibodies against the dominant strains of covid-19 compared with the original shot.

Blood from 80 volunteers collected seven days after the booster shot showed an increase in neutralizing antibodies against the BA.4 and BA.5 subvariants in a study, Pfizer and BioNTech said Thursday.

The vaccines were authorized without data showing their performance in humans. Pfizer and BioNTech plan to release additional data in coming weeks measuring immune responses one month following administration of the new bivalent booster. They have not shared data on the shot’s efficacy, which would offer a better measure of protection against widely circulating variants.

“While we expect more mature immune-response data from the clinical trial of our omicron BA.4/BA.5-adapted bivalent vaccine in the coming weeks, we are pleased to see encouraging responses just one week after vaccination in younger and older adults,” Pfizer Chief Executive Albert Bourla said.

“These early data suggest that our bivalent vaccine is anticipated to provide better protection against currently circulating variants than the original vaccine, and potentially help to curb future surges in cases this winter,” Bourla said.

The U.S. fall booster campaign has thus far faltered. Only 11.5 million Americans have been administered a newly modified vaccine, a fraction compared with previous booster campaigns.

On Wednesday, U.S. regulators expanded access to the new bivalent booster shots to include children 5 and older.