The shift would mean fewer shots recommended for children. But a Danish health official found the idea baffling, saying the United States was getting “crazier and crazier in public health.”

Lt. Gen. Francis L. Donovan, a Marine general with expansive experience in special operations and the Middle East, would take over after the abrupt departure of the previous commander.

Hundreds of people had rallied for the family in New York City after they were separated by Immigration and Customs Enforcement agents in November.