https://apnews.com/63d18f7e1fe86ceb6f8434fe4b1a8bc7 > U.S. health officials plan to offer COVID-19 booster shots to vaccinated Americans to shore up their protection amid the surging delta variant and evidence that the vaccines’ effectiveness is declining. A look at what we know about boosters and how they could help fight the coronavirus pandemic: > It’s common for protection from vaccines to decrease over time. A tetanus booster, for example, is recommended every 10 years.