Vaccine skeptics could see a significant win this week as the Centers for Disease Control and Prevention’s vaccine advisory panel weighs key changes to the childhood immunization schedule.
The Advisory Committee on Immunization Practices will hold its third and final meeting of 2025 on December 4 and 5 and is projected to vote on the future of the infant Hepatitis B vaccine and certain vaccine ingredients, both of which have raised concerns among medical experts amid the highly contentious vaccine policy environment.
Health and Human Services Secretary Robert F. Kennedy Jr. has been sharply criticized by the medical establishment, as well as some physician members of Congress, for his decision to fire the original ACIP members and replace them with medical professionals more aligned with his views on vaccine safety.
Kennedy faced a rocky confirmation process because of his advocacy for the debunked premise that the measles, mumps, and rubella vaccine causes autism. To get confirmed, he promised Sen. Bill Cassidy (R-LA), chairman of the Senate Health Committee, that he would not alter public information on the CDC website to link vaccines to autism.
But in November, two weeks before the ACIP meeting, the CDC made sweeping alterations to its website to instead say that the statement that vaccines do not cause autism “is not an evidence-based claim because studies have not ruled out the possibility that infant vaccines cause autism.”
It is unclear whether the website change is in any way related to the ACIP meeting or the committee’s working group findings on the cumulative effects of vaccine ingredients, such as aluminum adjuvants, which increase the vaccine recipient’s immune response.
Both the vaccine ingredients and the neonatal Hepatitis B vaccine have been proverbial “white whales” for the anti-vaccine movement for decades. Supporters of vaccines have argued that changes to these policies could have substantial public health effects, particularly since mandated insurance coverage of vaccines is tied to ACIP recommendations.
Disruptive changes to the childhood vaccine schedule could also eventually have implications for the 2026 midterm election for the GOP, as the vaccine portion of President Donald Trump and Kennedy’s “Make America Healthy Again” agenda has been less popular than some of their other policy goals, such as food reform.
Here is everything to know ahead of this week’s meeting.
Neonatal Hepatitis B vaccine
The ACIP is revisiting its conversation on the neonatal Hepatitis B vaccine after a scheduled vote to change recommendations was tabled during the September meeting, following intense debate among panelists. The December meeting is likely to be just as fiery and passionate.
CDC began recommending in 1991 that all infants receive a Hepatitis B vaccine during their first few hours of life to curb the spread of the deadly virus that causes liver disease and liver cancer.
Hepatitis B, which spreads through bodily fluids, has the most significant effect on infants born to Hepatitis B-positive mothers. Nine in 10 infants born to Hepatitis B-positive mothers will contract a chronic life-long form of the disease, and about a quarter of these will die of cirrhosis or liver cancer.
But Hepatitis B is colloquially considered a sexually transmitted disease, with homosexual males and intravenous drug users being the most at risk. That makes giving the vaccine to newborns, or even slightly older infants, ripe for common-sense criticism.
Trump himself has been an aggressive advocate of increasing the age of the first dose of the Hepatitis B vaccine until age 12, at which point the child’s immune system will be further developed, and he or she is more likely to be exposed to sex or drugs.
Supporters of the neonatal Hepatitis B vaccine, however, argue that infants most at risk of contracting the virus early in life are those also most likely not to follow-up, particularly lower-income and minority patients.
They also contend that a universal vaccine recommendation is necessary because it is not always possible to test the mother for the virus ahead of labor if she has not had access to prenatal care to test for the infection earlier in pregnancy.
Vaccine ingredients
Examining the potential negative interactions among the various vaccines given to children in the US has been a rallying cry for the MAHA movement since its inception during the 2024 presidential campaign.
During the June ACIP meeting, the first meeting after Kennedy’s abrupt termination of the former members, new chairman Martin Kulldorff announced that the committee would establish a new working group on the cumulative effects of vaccine ingredients on the childhood immunization schedule.
The Children’s Hospital of Philadelphia states that, before the age of 2, children in the US receive between 11 and 14 separate vaccinations, involving more than 25 injections. Between the ages of 3 and 18, they receive an additional eight shots, not including recommended annual COVID-19 and flu vaccines.
It is not yet clear whether the ACIP will vote on any vaccine ingredients during the December meeting, but it is on the draft agenda that the committee will discuss adjuvants and contaminants on the first day of the proceedings.
Public health experts are particularly concerned about aluminum adjuvants, which are used in at least eight of the childhood immunizations on the schedule, including Hepatitis B, whooping cough or DTaP, and HPV.
Aluminum adjuvants are used to generate a higher immune response for vaccines that do not contain live virus particles. For some immunizations, vaccines that do not have live virus particles are safer as they do not pose a risk of contracting the infection.
The CDC’s changed website on the link between autism and vaccines cites one study finding that aluminum adjuvants “had the highest statistical correlation with the rise in autism prevalence among numerous suspected environmental causes.” The study was authored by University of Colorado Boulder researcher Cynthia Nevison, who is also a contributing author to the anti-vaccine group Children’s Health Defense
Should ACIP vote to no longer recognize aluminum adjuvants as safe, vaccine makers say it could take years to develop alternatives that would get the committee’s stamp of approval. It would also mean that, in the meantime, insurance companies might not cover aluminum-containing vaccine products.
Election implications for the GOP
While the immediate consequences of the ACIP votes this week are comparatively niche, the longer-term implications could sway the 2026 midterm elections with voters reacting to Kennedy and the GOP’s broader vaccine policy.
As of October 9, only 9% of those surveyed by health policy organization FF reported strongly supporting Kennedy’s vaccine agenda, while another 28% somewhat supported it.
Partisanship had a sizable influence on approval or disapproval of Kennedy, but swing voters tended to align with Democrats, who oppose his stance on vaccines. Of the independents surveyed, 41% strongly disapproved and 26% somewhat disapproved of Kennedy’s vaccine policy.
Even among self-identified MAHA supporters in another KFF poll from October 15, only 9% identified as anti-vaccine, and roughly a quarter of MAHA parents said they skipped or delayed one or more of their child’s vaccines.
Support for the MMR and Polio vaccines is also high among MAHA parents, at 86% and 85%, respectively, with many stating that the immunizations are important for their children. That’s comparable to the respective 90% and 88% of total parents, regardless of MAHA affiliation.
Hepatitis B was not among the list of vaccines parents were asked about in the most recent KFF poll. Still, a different KFF poll found that only 5% of parents skipped the Hepatitis B vaccine for their child, and only 4% delayed the neonatal first dose.
However, it is possible that MAHA advocates within HHS may not heed public opinion polling data on vaccines as they head into 2026.
Calley Means, adviser to Kennedy and former White House adviser to Trump on health policy, said on the podcast “Culture Apothecary” hosted by Alex Clark that polling on vaccine support is “BS because what does it even mean to say you support vaccinations?”
“Those polls are being done by pharmaceutical companies to kind of skew the debate and give talking points to people,” Means said in November.