NEW YORK – In a significant shift, a federal vaccine advisory committee has decided to discontinue the long-standing guideline that all newborns in the United States receive the hepatitis B vaccine immediately after birth.

This decision has sparked strong criticism from numerous medical and public health professionals. The committee’s current members, selected by U.S. Health Secretary Robert F. Kennedy Jr., a prominent figure in the anti-vaccine movement until his recent appointment, are at the center of this contention.

Dr. William Schaffner, a vaccine specialist from Vanderbilt University with considerable experience in the Advisory Committee on Immunization Practices (ACIP) and its subgroups, expressed his disapproval, saying, “This is the group that can’t shoot straight.”

For many years, the government has advocated for the vaccination of infants against hepatitis B immediately after birth, a practice credited with averting a multitude of liver infection cases.

However, Kennedy’s ACIP has now suggested that the initial dose be administered only to newborns whose mothers have tested positive for the virus or in situations where the mother’s status is unknown.

For other infants, the choice of administering the vaccine at birth will rest with parents and healthcare providers. The committee has recommended that if the initial dose is not given at birth, the vaccination series should commence when the child reaches two months of age.

The vote passed 8-3.

“We are doing harm by changing this wording, and I vote no,” said committee member Dr. Cody Meissner.

The acting director of the Centers for Disease Control and Prevention, Jim O’Neill, is expected to decide later whether to accept the committee’s recommendation.

The decision marks a return to a public health strategy that was abandoned more than three decades ago.

Asked why the newly-appointed committee moved quickly to reexamine the recommendation, committee member Vicky Pebsworth on Thursday cited “pressure from stakeholder groups wanting the policy to be revisited.” She did not say who was pressuring the committee, and a spokesman for Kennedy did not respond to a question about it.

Committee members said the risk of infection for most babies is very low and that earlier research that found the shots were safe for infants was inadequate.

They also worried that in many cases, doctors and nurses don’t have full conversations with parents about the pros and cons of the birth-dose vaccination.

The committee members voiced interest in hearing the input from public health and medical professionals, but chose to ignore the experts’ repeated pleas to leave the recommendations alone.

Dr. Peter Hotez of the Texas Children’s Hospital Center for Vaccine Development in Houston declined to present before the group “because ACIP appears to have shifted its mission away from science and evidence-based medicine,” he said in an email to The Associated Press.

The committee gives advice to the director of the Centers for Disease Control and Prevention on how approved vaccines should be used. CDC directors almost always adopted the committee’s recommendations, which were widely heeded by doctors and guide vaccination programs. But the agency currently has no director, leaving acting director O’Neill to decide.

In June, Kennedy fired the entire 17-member panel earlier this year and replaced it with a group that includes several anti-vaccine voices.

Hepatitis B is a serious liver infection that, for most people, lasts less than six months. But for some, especially infants and children, it can become a long-lasting problem that can lead to liver failure, liver cancer and scarring called cirrhosis.

In adults, the virus is spread through sex or through sharing needles during injection drug use. But it can also be passed from an infected mother to a baby.

In 1991, the committee recommended an initial dose of hepatitis B vaccine at birth. Experts say quick immunization is crucial to prevent infection from taking root. And, indeed, cases in children have plummeted.

Still, several members of Kennedy’s committee voiced discomfort with vaccinating all newborns. They argued that past safety studies of the vaccine in newborns was limited and it’s possible that larger, long-term studies could uncover a problem with the birth dose.

But two members said they saw no documented evidence of harm from the birth doses and suggested concern was based on speculation.

The panel was to vote Thursday, but voted to postpone after some members said they had just received the densely-worded vote proposals and wanted clarification and more time to consider it.

Three panel members asked about the scientific basis for saying that the first dose should be delayed for two months for many babies.

“This is unconscionable,” said committee member Dr. Joseph Hibbeln, who repeatedly voiced opposition to the proposal during the sometimes-heated two-day meeting.

The committee’s chair, Dr. Kirk Milhoan, said two months was chosen as a point where infants had matured beyond the neonatal stage. Hibbeln countered that there was no data presented that two months is an appropriate cut-off.

Some observers criticized the meeting, noting recent changes in how they are conducted. CDC scientists no longer present vaccine safety and effectiveness data to the committee. Instead, people who have been prominent voices in anti-vaccine circles were given those slots.

The committee “is no longer a legitimate scientific body,” said Elizabeth Jacobs, a member of Defend Public Health, an advocacy group of researchers and others that has opposed Trump administration health policies.

In a statement, she described the meeting this week as “an epidemiological crime scene” — a slaughter of how disease control professionals usually examine and act on evidence.

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AP writer Laura Ungar in Louisville, Kentucky, contributed to this report.

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