Kennedy's advisory panel is expected to vote on hepatitis B and MMRV vaccines

Kennedy, a leading antivaccine activist before becoming the nation's top health official, has made or proposed numerous changes to the nation's vaccine system, including firing the entire 17-member panel earlier this year and replacing it with a group that includes several anti-vaccine voices.

The morning's discussion focused on a combination vaccine called MMRV, which protects against measles, mumps, rubella and chickenpox, which is also known as varicella.

The advisers planned to vote on a proposal recommending the shot not be given to children younger than 4 because of rare instances of feverish seizures associated with the first dose that is currently given to kids between ages 1 and 2.

On Thursday, committee member Dr. Cody Meissner said such seizures may be "a very frightening experience" for families, but medical experts agree they're not linked to brain function or school problems.

The panel last dealt with the issue in 2009, when it said either the combination shot or separate MMR and varicella shots were acceptable for the first dose, but that separate doses were generally preferred. Today, 85% of kids receive separate doses for the first round, according to information presented at the meeting.

Some doctors and public health experts say they are not aware of any new safety data that would explain the revisiting of those vaccination recommendations — and, in fact, many of the studies discussed Thursday were more than a decade old.

Dr. Richard Haupt, a vice president at Merck, which makes the MMRV vaccine ProQuad, said it's been evaluated through clinical trials and post-approval studies, and the slight increase in feverish seizures after first dose led to current CDC recommendations. Combination vaccines improve completion and on-time vaccination at a time when the nation is seeing a troubling decline in vaccination coverage, he said.

"Considering these trends, any policy decision that compromises the clarity or consistency of vaccination guidance ... has the potential to further diminish public confidence," he told the committee.

Dr. Mysheika Roberts, health department director in Columbus, Ohio, said one of the benefits of the combined vaccine is it limits the number of shots a child gets, which is useful in certain populations of patients, such as newly arrived immigrants who need lots of vaccines at the same time.

But she also acknowledged concerns about feverish seizures among children under age 4 and said, "maybe the guidance needs to be tweaked a little bit on that."

The panel, the Advisory Committee on Immunization Practices, makes recommendations to the director of the Centers for Disease Control and Prevention on how already-approved vaccines should be used. CDC directors have almost always accepted those recommendations, which are widely heeded by doctors and guide vaccination programs.

In his opening remarks, committee Chairman Martin Kulldorff defended the group against critics who say it leans toward anti-vaccine views.

"The members of this ACIP Committee are committed to reassuring the public and restoring public confidence by removing unnecessary risks and harms whenever possible. That is a pro-vaccine agenda," Kulldorff said.

He later added: "We welcome scientific critique of any of our votes, as there are gray areas due to incomplete scientific knowledge."

The panel is currently discussing a vaccine against the liver disease hepatitis B.

Information on the meeting agenda suggests the committee may be poised to roll back — at least partly — a longstanding recommendation that virtually all U.S. children get an initial dose of hepatitis B vaccine right after birth.

The American Academy of Pediatrics and many public health officials support that decades-old practice.

Roberts said rates of the liver disease among children have dropped tremendously since it was put into place.

"I don't understand the rationale of why we would stop providing that vaccine and that guidance to babies when we've seen such great progress in that area," said Roberts, who was scheduled to join the vaccine panel but was dismissed by Kennedy. "If it's not broken, why change it?"

Doctors' groups and public health organizations have voiced alarm about Kennedy and his new panel. Concern intensified in May, when Kennedy announced he was removing COVID-19 shots from the CDC's recommendations for healthy children and pregnant women. The move was heavily criticized by doctors' groups and public health organizations, and prompted a lawsuit by the American Academy of Pediatrics and other groups.

The committee is scheduled to make COVID-19 vaccine recommendations on Friday.

The AAP and some others groups have issued their own vaccination recommendations, which disagree with recommendations put out by federal officials this year.

In recent weeks, several states have announced policies to help residents maintain access to vaccines, in some cases signing orders that ensure COVID-19 vaccinations at pharmacies without individual prescriptions. Wisconsin this week joined a list of more than a dozen to take steps, when Gov. Tony Evers signed an executive order for state health officials to follow the guidance of national physician organizations.