The public health world is nervously bracing for drastic changes to childhood immunization schedules, which would further limit access to vaccines, as the Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices (ACIP) meets Thursday and Friday.

The questions the panel will vote on have not been disclosed, but speculation has run high that the panel will endorse drastic changes to the current immunization recommendations, including the guidance to immunize newborns against hepatitis B. It will also discuss the MMRV and COVID-19 vaccines.  

Earlier this year, Health and Human Services (HHS) Secretary Robert F. Kennedy Jr. fired all 17 sitting members of ACIP and replaced them with his choices, including several known vaccine critics. Just days before the meeting, HHS announced five additions to the panel, including people who have publicly spoken out against COVID-19 vaccines. 

When the newly remade panel met for the first time in June, the members voted in favor of only recommending flu shots that don’t contain the mercury-based preservative thimerosal. During that meeting, Lyn Redwood, former head of the anti-vaccine group Children’s Health Defense that Kennedy founded, was allowed to give a presentation in which she strongly suggested thimerosal was causing detrimental effects on children. 

As NPR reported this week, former CDC officials suspect the panel will recommend delaying hepatitis B vaccinations. 

Demetre Daskalakis, the former director for the National Center for Immunization and Respiratory Diseases, told the outlet, “There is going to likely be a discussion about hepatitis B vaccine, very specifically trying to dislodge the birth dose of hepatitis B vaccine and to push it later in life.” 

Both former CDC Director Susan Monarez and the agency’s former Chief Medical Officer Debra Houry echoed similar concerns during a Senate Health Committee hearing on Tuesday.  

According to Monarez, the ACIP meeting was at the core of her abrupt termination last month, just weeks after she had been confirmed by the Senate. Since being ousted, she has repeatedly claimed Kennedy asked her to preapprove any recommendations that come out of the committee, regardless of the evidence. Monarez said she refused. 

Kennedy has denied making that request of Monarez. 

“We got into an exchange where I had suggested that I would be open to changing childhood vaccine schedules if the evidence or science were supportive, and he responded that there was no science or evidence associated with a childhood vaccine schedule,” Monarez said Wednesday. “And he elaborated that CDC had never collected the science or the data to make it available related to the … safety and efficacy.” 

Houry told the Senate committee the manner in which the meeting was set up was also unusual. She told Sen. Bill Cassidy (R-La.), the committee chair, the agenda had been put together by political appointees at HHS, with little input from scientific staffers, which she says she hadn’t seen in the decade she had worked at the CDC. 

“For this meeting, we didn’t have work groups other than one for COVID. So, CDC scientists were being asked by ACIP to develop questions and recommendations,” Houry said. “I did suggest additional questions that the hepatitis B work group look at so that they could look at differences in age groups. The senior adviser was concerned that could bias moving away from a birth dose.”

Sen. Ed Markey (D-Mass.) noted the panel is expected to vote on a proposal to move the hepatitis B vaccine recommendation to age 4. Houry said such a change “would not be based on data.”

Key senators are anxious about this vote. Cassidy, a hepatologist by trade, used his closing remarks Wednesday to speak in support of the hepatitis B vaccine, telling reporters after the hearing that recommendations to change the current immunization schedule should not have Americans’ confidence. 

He argued a recommendation to immunize newborns against hepatitis B is not a mandate and pointed to the success that the shot has had, saying, “we have decreased from 20,000 kids a year getting hepatitis B to like 20 a year. That’s exponential decline.” 

State and local health leaders are bracing for the changes expected to be endorsed by the panel, including the possibility that insurers won’t cover these shots once they’re no longer recommended by federal bodies. 

“If the ACIP were to decide that the hepatitis B vaccine should no longer be given at birth, hospitals could still vaccinate newborns with private insurance, however, they would no longer be able to vaccinate newborns on Medi-Cal or Medicaid, since those children rely on the [Vaccines for Children ] program. So, this type of decision could leave our most vulnerable and at risk,” said Muntu Davis, family physician and Health Officer for Los Angeles County. 

Last week, Los Angeles County confirmed the death of a school-aged child due to a rare complication stemming from a measles infection they’d contracted years earlier. 

“We get a lot of our vaccine for the uninsured, underinsured, for the [CDC’s] Vaccines for Children program,” said Phil Huang, family physician and Director of the Dallas County Health and Human Services, at a press briefing Wednesday.  

“Talking to the state, it sounds like the ACIP guidance is going to direct probably what are the recommendations and allowable uses for our COVID vaccine in particular,” he added. “And if it follows then … what FDA has put in their guidance, then that would potentially restrict a lot of our population — uninsured, underinsured — from being able to access the vaccine.” 

The trade group that represents American health insurers, AHIP, said this week that companies would continue to cover all vaccines that were recommended by ACIP at the start of this month until at least the end of 2026.

“While health plans continue to operate in an environment shaped by federal and state laws, as well as program and customer requirements, the evidence-based approach to coverage of immunizations will remain consistent,” AHIP said.