WASHINGTON (AP) — Half of all adults in the U.S. have now received at least one COVID-19 shot. That’s according to the Centers for Disease Control and Prevention. The announcement on Sunday marks another milestone in the nation’s largest-ever vaccination campaign. It also leaves more work to do to convince skeptical Americans to roll up their sleeves. The CDC says almost 130 million people 18 or older have received at least one dose of a vaccine, or 50.4% of the total adult population. Almost 84 million people adults, or about 32.5% of that population, have been fully vaccinated.