It cannot be easy to lead the agency that handles infectious diseases in the midst of an international pandemic. Still, the director of the Centers for Disease Control and Prevention should at least be able to prove she is up to the task. Dr. Rochelle Walensky has repeatedly proved herself unfit and unreliable. She needs to go.

This week, under her direction, the CDC changed its guidance to encourage fully vaccinated adults to put their masks back on in certain situations. This flip-flop is not based in science but in hysteria. Vaccinated adults are not at any more risk of falling seriously ill from the coronavirus and its variants now than they were two months ago when Walensky declared that there was no longer any reason for vaccinated adults to wear masks.