Health and Human Services Secretary Robert F. Kennedy Jr.’s moves to upend decades of vaccine policy could hit patients hardest in their wallets, as shifting guidance over shots could make insurance coverage confusing and scattershot.

Just two days after retiring the entirety of the US Centers for Disease Control and Prevention’s vaccine advisory panel, US Health and Human Services Secretary Robert F. Kennedy Jr. has appointed several prominent critics of the government’s Covid-19 response to that committee.

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,