Powerful federal advisers this week are expected to consider a controversial change to how babies are immunized against hepatitis B and to reexamine practices for more than a dozen other childhood vaccines, including those for measles, mumps, whooping cough and polio.
The Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices (ACIP) meets Thursday and Friday to review fundamental elements of the childhood immunization schedule — the timetable pediatricians use to deliver more than 30 doses protecting against multiple diseases. The meeting comes after sweeping personnel changes at the committee by Health and Human Services Secretary Robert F. Kennedy Jr., who has long questioned vaccine safety and effectiveness.
Supporters of the administration’s moves welcome the scrutiny. Mary Holland of Children’s Health Defense, a nonprofit that opposes vaccines and was co-founded by Kennedy, said the changes are revealing “truth telling about vaccines” and criticized the medical establishment. But many public health experts fear the meeting will further erode vaccination rates and prompt a resurgence of preventable illnesses.
“We now seem to have entered a dangerous new phase in Secretary Kennedy’s campaign to shut down scientific expertise, silence the best available evidence, and replace it with his own personal agenda,” said Dr. Sean O’Leary, a pediatric infectious disease professor who chairs the American Academy of Pediatrics’ committee on infectious diseases.
ACIP, created in 1964, has long been viewed as a definitive source on childhood vaccines. Its recommendations shape clinicians’ practices and influence insurance coverage. But the committee’s credibility with mainstream medical organizations has diminished since Kennedy replaced its members in June with his own slate. The revamped committee has pared back collaborations with groups such as the American Academy of Pediatrics and has relied less on CDC experts.
The September ACIP meeting devolved into confusion when a scheduled vote on the hepatitis B vaccine was tabled. The committee’s chair was recently replaced; the new chair, Dr. Kirk Milhoan, is a pediatric cardiologist and a fellow with the Independent Medical Alliance, an organization that has promoted COVID treatments like ivermectin despite evidence they are ineffective.
Confidence in the CDC was further shaken last month when the agency altered its position on whether vaccines might cause autism — a theory long debunked by extensive research but championed by Kennedy and some critics. In response, independent medical groups including the American Academy of Pediatrics and the American Academy of Family Physicians, and a new Vaccine Integrity Project at the University of Minnesota, have issued separate guidance that some states are following.
Vaccine schedule under review
A new ACIP working group has been tasked with scrutinizing the childhood vaccine schedule. Public health officials worry the timing of that review coincides with a rise in vaccine-preventable disease outbreaks tied to falling immunization rates.
“We have seen more measles cases in our country this year than we have in recent history. In my own community, we’re seeing quite significant upticks in pertussis,” said Dr. Raynard Washington, director of Mecklenburg County Public Health in Charlotte, N.C. He warned that any barriers to vaccination created by bureaucracy or process threaten public health.
Vaccine proponents emphasize that each vaccine and its timing are chosen based on evidence of when a child’s immune system responds best and when the child is most at risk for disease. “Every vaccine on that schedule and the recommended timing of it exists for a reason,” O’Leary said. Delaying or spacing out vaccines, he added, simply increases children’s risk.
Critics sometimes argue that multiple vaccine antigens and ingredients could overwhelm an infant’s immune system. Experts counter that children routinely encounter far more immune stimulation from everyday microbes than from vaccines, and that modern vaccines have been refined to minimize unnecessary ingredients. “These newer vaccines are a good thing. They save lives,” O’Leary said.
A possible change for the hepatitis B shot
One likely action from the committee is a vote to change the longstanding recommendation that all newborns receive a hepatitis B vaccine within 24 hours of birth. Options under consideration could include delaying the first dose or requiring a more detailed parental discussion before giving it.
Advocates of changing the universal birth dose say hepatitis B is often spread via sexual contact or injection drug use and that increased screening of pregnant women, with vaccination only for infants born to infected mothers, could suffice. They note some other countries do not give the newborn dose.
Public health experts warn this is risky. Hepatitis B is highly infectious and can be spread through exposure to infected blood or body fluids, and even via common household objects contaminated with infected blood. Most infants who acquire hepatitis B become chronically infected, facing higher lifetime risks of liver disease, failure and cancer.
A new analysis presented to ACIP authors suggests that delaying hepatitis B vaccination by a few months could lead to more than $222 million in excess healthcare costs and hundreds of preventable deaths each year. “Universal vaccination has been the cornerstone of hepatitis B elimination efforts for decades,” said Eric Hall, an epidemiologist at Oregon Health & Science University and a co-author on the analysis. He urged preserving the policy that has driven dramatic drops in hepatitis B infections.
O’Leary stressed the vaccine’s strong safety record and the practical problems of delaying the birth dose: subsequent doses are given as part of combination vaccines, so changing timing could complicate schedules and increase missed vaccinations. He also noted that pediatricians work with parents and that families are involved in immunization decisions.
Concerns about splitting combination vaccines
Experts are also alarmed that ACIP is examining splitting the MMR vaccine, which protects against measles, mumps and rubella in a single shot. Giving three separate shots would require more clinic visits and more injections, raising the likelihood that children would miss doses.
Aluminum adjuvants under scrutiny
The committee is studying the safety of aluminum adjuvants — compounds containing small amounts of aluminum used for decades to boost immune responses to several vaccines, including some for diphtheria, tetanus, hepatitis and influenza. The working group’s mandate includes evaluating whether either of two different aluminum adjuvants might increase asthma risk.
Most public health experts say there is no credible evidence aluminum adjuvants are unsafe; large studies have not shown harms, and people are exposed to far more aluminum daily from food, consumer products and the environment than from vaccines. Critics nevertheless claim aluminum can raise risks for conditions such as autism or attention deficit hyperactivity disorder, assertions that have not been supported by rigorous research.
“Based on large, long-term studies and immunology research, there is no evidence that vaccines cause either allergies or autoimmune disorders,” Dr. Frank Virant of the American Academy of Allergy, Asthma & Immunology told reporters.
Removing aluminum from vaccines would impair their effectiveness. There are no ready substitutes, and reformulating vaccines without aluminum could take years.
What’s at stake
Public health experts say the stakes are high: the childhood immunization schedule is the result of decades of research and practice designed to maximize protection when children are most vulnerable. Changes to recommendations, especially ones that reduce vaccine uptake, could reverse long-standing gains against infectious diseases. As ACIP meets, the debate lays bare deeper disputes over scientific authority, trust in public health institutions and how best to protect children’s health.