Regulators, experts take up thorny vaccine study issues

The U.S. regulators who will decide the fate of COVID-19 vaccines are taking an unusual step: Asking outside scientists if their standards are high enough. The Food and Drug Administration may have to decide by year’s end whether to allow use of the first vaccines against the virus. Thursday, a federal advisory committee pulls back the curtain on that decision process, debating whether the guidelines FDA has set for vaccine developers are rigorous enough.