Pfizer booster spurs immune response to new omicron subtypes

By LAURAN NEERGAARD
AP Medical Writer

Pfizer said its updated COVID-19 booster may offer some protection against newly emerging omicron mutants even though it’s not an exact match. Few Americans have gotten updated boosters made by Pfizer and rival Moderna, shots tweaked to target the BA.5 omicron strain that until recently was the most common type. Pfizer reported Friday that the updated booster spurs a bigger jump in antibodies against some even newer omicron subtypes, including the worrisome BQ.1.1, than another dose of original vaccine.