As Covid-19 vaccine makers prepare Omicron-specific shots, federal health authorities say there are signs they might not be necessary.
Research is continuing, however, and industry and global-health officials say doses targeting the highly transmissible new variant might be needed longer-term, especially if it winds up crowding out earlier strains globally.
Differing opinions on the need for Omicron-targeted shots highlights the persisting uncertainty around current vaccines’ relative efficacy against the variant weeks after it began sweeping the U.S.
Researchers designed the existing Covid-19 shots to fight the original coronavirus strain that predominated in 2020. Since then, the vaccines have remained effective against newer variants like Delta that have emerged and overtaken the initial strain. But then came the Omicron... right on its own methodology.
