The Food and Drug Administration signed off on extending COVID-19 boosters to Americans who got the Moderna or Johnson & Johnson vaccine and said anyone eligible for an extra dose can get a brand different from the one they received initially. The FDA's decisions mark a big step toward expanding the U.S. booster campaign, which began with extra doses of the Pfizer vaccine last month. However, the Centers for Disease Control and Prevention will first consult an expert panel later this week before finalizing official recommendations for who should get boosters and when. The latest moves would expand by tens of millions the number of Americans eligible for boosters and formally allow "mixing and matching" of shots — making it simpler to get another dose.