The Food and Drug Administration is expected to approve the new Covid vaccine as early as Thursday, according to two sources familiar with the agency’s planning. It’s the third time the vaccines have been updated to match circulating strains since the original series. The shots should be available within days. The FDA and HHS declined to comment on the expected update. The timing of the new vaccines — last year's rollout was in mid-September — is significant, since most of the U.S. is still caught in the summer wave of Covid illness. As of Monday, the Centers for Disease Control...