U.S. health officials want to make COVID-19 vaccinations more like the annual flu shot. The Food and Drug Administration on Monday proposed a simplified approach for future vaccination efforts, allowing most adults and children to get a once-a-year shot to protect against the mutating virus. This means Americans would no longer have to keep track of how many shots they’ve received or how many months it’s been since their last booster. The proposal comes as boosters have become a hard sell. While more than 80% of the U.S. population has had at least one vaccine dose, only 16% of those...