Mr. Biden’s announcement concerned regulators at the F.D.A., given that it came before the agency had evaluated the data on whether the shots were needed. Two top vaccine officials soon announced that they would depart the agency this fall, in part over the issue.
Speaking on NBC’s Meet the Press, Dr. Fauci said Mr. Biden “wasn’t getting ahead of the science,” noting that the president always said the plan was dependent on authorization by the F.D.A.
“I think people are not understanding the difference of planning for something and actually what element of that, what proportion of it, you’re actually going to roll out,” he said. “And that’s exactly what happened.”
Dr. Fauci also asked Americans to be patient and wait until they are eligible for an additional shot, adding that it would be only weeks before data on whether an extra shot of the Moderna and Johnson & Johnson vaccines was needed.
“We’re working on that right now to get the data to the F.D.A., so they can examine it and make a determination about the boosters for those people,” he said. “They’re not being left behind by any means.”