https://apnews.com/f13611719ad8d1655ed7b354af75a9a9 > WASHINGTON (AP) — The U.S. is getting a third vaccine to prevent COVID-19, as the Food and Drug Administration on Saturday cleared a Johnson & Johnson shot that works with just one dose instead of two. > Health experts are anxiously awaiting a one-and-done option to help speed vaccinations, as they race against a virus that already has killed more than 510,000 people in the U.S. and is mutating in increasingly worrisome ways.