New coronavirus boosters are just around the corner following authorization Wednesday by federal regulators. The updated shots are designed to provide a stronger shield against the BA.4 and BA.5 omicron subvariants still causing tens of thousands of infections and hundreds of deaths every day in the United States. The boosters will be part of a campaign by the federal government, to be kicked off within days, to persuade Americans to bolster their immune defenses before a potential surge in covid-19 cases as cooler weather arrives in the fall. But the updated boosters have generated some controversy and confusion. Here's what...