It is following a version of its traditional, cautious process for vaccine approval. That process has historically had some big advantages, reducing the chances that Americans end up taking a faulty drug. To move much more quickly would risk undermining the public’s confidence in the F.D.A. and, by extension, the medicines it approves, Dr. Peter Marks, who oversees the process, has argued.

But I think the F.D.A.’s leaders have failed to understand how most Americans really think about the vaccines. It is different from the way that scientists and epidemiologists do. It’s less technical and based more on an accumulation of the publicly known facts.

It reminds me of another example of expert miscommunication, early in the pandemic. Back then, public health officials made highly technical statements about masks that many people interpreted as discouragement from wearing them. These statements ignored the many reasons to believe that masks could make a difference (like their longtime popularity in Asia to prevent the spread of viruses) and focused instead on the absence of studies showing that masks specifically prevented the spread of Covid.