The U.S. rollout of Covid-19 booster shots has been defined, unfortunately, by confusion. Last month, the Food and Drug Administration approved additional shots for many people who had received the Pfizer vaccine, but not for anyone who’d gotten Moderna or Johnson & Johnson. And in contrast to health authorities in several other countries, the FDA did not sanction allowing people to get booster shots that didn’t match their original vaccinations.
So news that the agency may soon endorse such mixing comes as a welcome surprise. As soon as this week, it is expected to approve boosters of the Moderna and J&J vaccines as well as mixing of shots. This is the right decision, and it steers the agency toward the greater flexibility it needs.
