U.S. vaccine advisers¡¯ decision to scrap longstanding guidance on hepatitis B shots will expose more children to the harmful virus and may signal how other evidence-based vaccine policies can be undermined, doctors and disease experts have said.

Since 1991, U.S. health officials have recommended universal vaccination for infants against hepatitis B, with the first of three shots administered very soon after birth. The move has cut infections dramatically and saved lives, federal data shows.

On Friday, an advisory panel appointed by Health Secretary Robert F. Kennedy Jr. said a birth dose should only be given to newborns whose mother tests positive for hepatitis B or whose status is unknown. In cases where the mother tests negative, parents should decide with their doctors when, or even if, their children should receive any hepatitis B vaccines, the panel said.