A top-level vaccine panel in the United States government has voted to peel back guidance that newborn babies should receive a vaccine to shield against hepatitis B, a virus that can cause chronic liver problems.

On Friday, the Advisory Committee on Immunization Practices (ACIP) voted eight to three to rescind the medical advice, which has helped make hepatitis B vaccines a routine part of post-natal care.

Instead, ACIP approved new guidance that encourages parents who have no history of hepatitis B infection to speak with their healthcare provider about whether to administer the vaccine to their infants.

It also continues to advise administering the vaccine for children of mothers who have hepatitis B.

Medical experts and even pharmaceutical companies quickly denounced the change as dangerous, warning that it could encourage parents to leave their children unvaccinated.

The change is considered the biggest move so far under Secretary of Health and Human Services Robert F Kennedy Jr to change vaccination practices in the US.