Pfizer’s updated COVID-19 booster significantly revved up adults’ virus-fighting antibodies, the company said Friday, releasing early findings from a rigorous study of the new shots. Booster doses tweaked to target the most common omicron strain rolled out in early September, and the Food and Drug Administration said the latest data should spur more Americans to get one — especially before another expected wave of cases as people travel for Thanksgiving. Pfizer said people 55 and older who got the omicron-targeting booster had four-fold higher antibody levels than those given an extra dose of the original vaccine.