AdvertisementPfizer says its tweaked COVID-19 shots boost protection against the omicron variantJune 25, 2022The Associated PressfacebookEmailA syringe is prepared with the Pfizer COVID-19 vaccine at a vaccination clinic in Chester, Pa., on Dec. 15, 2021. Pfizer says tweaking its COVID-19 vaccine to better target the omicron variant is safe and boosts protection. (AP)
