“In the United States, “it turns out to get crazier and crazier in public health from month to month,” Dr. Hviid said. “It is surreal, and it is difficult, from a Danish perspective, to understand what’s going on.”

“They’re going to bring back suffering and death,” said Dr. Sean O’Leary, chair of the infectious disease committee for the American Academy of Pediatrics. “I don’t say that with any hyperbole, that’s exactly what’s going to happen.”