Together, Moderna’s announcement and Marks’s comment seem to suggest that the F.D.A. is eager to approve a vaccine for young children as soon as possible. Other evidence, however, indicates the opposite.

On CNN last week, Dr. Anthony Fauci, a top Biden administration Covid adviser, suggested that the F.D.A. would not approve a Moderna vaccine for young children until it could simultaneously approve one from Pfizer. Approving two vaccines at different times, he said, could “confuse people.” An article in Politico offered the same explanation, reporting that regulators wanted to postpone any action until it could approve both vaccines at once.

This planned delay raises two big questions. One, why does the government think Americans are incapable of handling different approval dates? (Zeynep Tufekci, a Times columnist, argues that Americans can handle it.) Two, why is the federal government telling us conflicting stories — one in which the F.D.A. is deliberately delaying approval and another in which the agency is merely waiting for Moderna and Pfizer to submit the necessary information?