There was a notable absence last week when U.S. Health and Human Services Secretary Robert F. Kennedy Jr. announced in a 58-second video that the government would no longer endorse the COVID-19 vaccine for healthy children or pregnant women.

Pediatric infectious disease expert Dr. Lakshmi Panagiotakopoulos resigned on Tuesday as co-leader of a U.S. CDC working group that advises outside experts on COVID-19 vaccines and is leaving the agency,