Pfizer Inc.’s COVID-19 vaccine declined in protection against hospitalization after four months, while Moderna Inc.’s remained stable, U.S. researchers found in an analysis of data from 21 U.S. hospitals across 18 states.
Two doses of either vaccine provided more protection against hospitalization than the one-dose Johnson & Johnson vaccine, the study found, though Pfizer’s advantage over J&J narrowed over time, according to the study published Friday by the Centers for Disease Control and Prevention with collaborators across the country. All three vaccines provided substantial protection after four months — Moderna’s was 92% effective against hospitalization by then, with Pfizer’s at 77% and J&J at 68%.
The data, published Friday, may influence the debate over whether Americans should receive a third dose of vaccine to ward off the virus. Advisers to the Food and Drug Administration are expected to vote Friday on whether to recommend a booster shot, and they’ve mostly had to rely on data from Israel and the U.K. on whether the shots’ effectiveness wanes over time.