() A key vaccine advisory panel has decided not to go ahead with a vote on whether to delay the first dose of the hepatitis B vaccine for newborns.

The panel has come under scrutiny after Health Secretary Robert F. Kennedy Jr. fired previous panel members and replaced them with a group that has a history of being skeptical of vaccines, despite decades of evidence showing that childhood vaccines are safe and effective.

The group advises the Centers for Disease Control and Prevention on U.S. vaccination schedules and earlier on Friday voted to delay giving children a combined measles, mumps, rubella and varicella (chicken pox) vaccine until age four.

Hepatitis B is a severe liver infection that may be acute or chronic. Those with hepatitis B are at increased risk for liver failure and liver cancer.

Hepatitis B can be contracted through bodily fluids, including saliva, blood and sexual fluids. While commonly thought of as a sexually transmitted infection, hepatitis B can be transmitted from mother to child during birth, through shared items like toothbrushes or close contact with infected people, including living in the same household.

Children under five may not show symptoms of hepatitis B, which can lead to unknown transmission to other children through normal childhood roughhousing, for example, via a scraped knee or other injury. The virus can also survive for seven days outside the body, making it possible for traces of blood on playground equipment or desks to be a source of infection.

The first dose of the hepatitis B vaccine is typically given at birth to protect infants and it has been shown to be safe with no links to chronic health conditions or harm.

In 1990, before the vaccine was universally given to newborns, the rate of hepatitis B in those under 19 was 3.03 per 100,000 people, according to CDC data. In the decades since the universal vaccine was implemented, the rate dropped to less than 0.1 per 100,000 people under 19 in 2022.

However, there has been a push from those who are anti-vaccine to stop giving the shots at birth. Opponents have argued that it is given too early and suggest that only mothers who are known to be positive for hepatitis B should get their newborns vaccinated.

Proponents of the vaccine note that pregnant people can become infected after testing negative, tests can provide false results and the possibility of other routes of exposure makes a universal vaccine necessary.

The advisory panel cited inconsistency in proposed policy changes as a reason to cancel the vote on delaying the vaccine. It is not clear how the group will proceed going forward.