The already tumultuous landscape of U.S. vaccine policy faces more turmoil in what’s anticipated to be a politically charged two-day meeting of a recently overhauled advisory panel to the Centers for Disease Control and Prevention.
The Advisory Committee on Immunization Practices (ACIP) is an independent panel of experts that has traditionally met three times a year to make science-based recommendations about who should receive certain vaccines. But this year the Trump administration’s efforts to undermine science and public health has upended the committee. Just yesterday former CDC director Susan Monarez, who led the agency for a month, testified to the Senate about her experience of being pushed out of office for not condoning attacks on vaccines unsupported by evidence. Most dramatically, Robert F. Kennedy, Jr., secretary of health and human services and a veteran antivaccine activist, fired the panel’s membership, with the newest appointees announced only days ago.
On September 18 and 19, the committee is holding its second meeting of the year, and experts now worry that the new ACIP members will continue eroding public access to lifesaving vaccinations. Already, one in six parents in the U.S. reports delaying or skipping a vaccine for their child, according to a recent poll.
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“I fear for the health of children in this country,” says Paul Offit, a pediatric infectious diseases specialist at Children’s Hospital of Philadelphia. “RFK, Jr.’s goal is to make vaccines less available, less affordable and more feared. That’s his goal, and he’s doing a great job of it.”
ACIP’s decisions are important because they dictate the price of lifesaving preventive care. The Affordable Care Act requires private insurance companies to cover ACIP-recommended vaccines at no cost; government-run insurance programs, including the Vaccines for Children program, which covers half of childhood vaccines administered nationwide, also base costs on the panel’s decisions.
At this week’s meeting, the newly reconstituted panel will discuss three vaccines: the combined measles, mumps, rubella and varicella vaccine, the hepatitis B vaccine and this year’s updated COVID shots.
The meeting’s agenda is a departure from ACIP’s norm, says Edwin Asturias, a pediatric infectious disease specialist and epidemiologist at the University of Colorado, who joined ACIP in July 2024 and was dismissed during Kennedy’s overhaul of the committee earlier this year. “This is one of the shortest agendas that we have seen for a long time from ACIP,” Asturias says. “Typically, ACIP has a lot of things to look through because there’s a lot of vaccines that are advancing through different aspects of development, as well as new data being generated.” Meetings in 2024 each discussed at least eight different vaccines.
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Asturias and other public health experts are particularly worried the meeting will institutionalize attacks on the childhood vaccine schedule—a carefully choreographed, evidence-based timeline of vaccines given to kids in their earliest years.
“The childhood immunization schedule has proven to be very effective at reducing a lot of diseases that cause a lot of pain, suffering, and death in children,” Asturias says.
The meeting will be livestreamed on both September 18 and September 19. Here’s what experts are keeping an eye on.
This story will be updated throughout the meeting.
The Measles, Mumps, Rubella and Varicella Vaccine
About the Vaccine
This vaccine offers protection against four diseases—measles, mumps, rubella and chicken pox, or varicella—in a single shot. It’s distinct from the measles, mumps and rubella (MMR) vaccine and was authorized in the U.S. for use in children between one and 12 years old in 2005, about a decade after the introduction of an independent vaccine that only protects against varicella zoster, the virus that causes chicken pox. The preferred and ACIP-recommended approach has been to administer separate MMR and varicella vaccines at 12 to 15 months old and then to give an additional combined shot at four to six years old to reduce the cumulative number of vaccines and visits required, Asturias says.
About the Diseases
Measles is one of the most contagious viruses known to science; doctors have no cure for the infection and can only treat its symptoms. Most people who catch measles develop a high fever and a characteristic rash, but extreme cases can cause inflammation in the brain—and in a small number of cases, usually in children, the virus lingers dormant in the nervous system for years before causing fatal inflammation. Mumps is a viral infection characterized by the swelling of certain salivary glands and can also trigger miscarriage early in pregnancy. Rubella, sometimes called German measles, is unrelated to measles but is also characterized by a rash. When contracted early in pregnancy, the infection causes serious birth defects in about 90 percent of cases. The varicella-zoster virus causes not just the itchy chickenpox rash but sometimes systemic infections, pneumonia and brain swelling. In addition, the virus can decades later trigger a painful rash called shingles.
What to Watch For
The ACIP agenda notes a two-hour block to discuss the MMRV vaccine, including a presentation on febrile seizure, a type of convulsion, following the vaccine—a very rare complication, seen predominantly in children between 12 and 23 months old.
This known side effect is why doctors tend to give children their first dose of MMR and varicella protection as two separate injections, then switch to the combined vaccine for kids older than the window in which there is a slightly higher risk of febrile seizures. Asturias worries that ACIP will decide to remove the combination vaccine option for parents looking to reduce the number of vaccines their children receive, in turn potentially reducing protection against these four infections. Such a change would “likely make it more complicated for families,” he says.
He’s also particularly worried that removing the MMRV vaccine would mean children miss out on the second dose of protection against measles—proven essential in effectively lowering cases. When the U.S. required only one dose of measles vaccination in the late 20th century, case rates remained high. It was only when the CDC began requiring a second dose that numbers fell. “We know that that second shot is very important,” Asturias says.
When to Watch
Hearings begin at 11 A.M. EDT on Thursday, with a vote on the vaccine itself and on its inclusion in the Vaccines for Children program scheduled for 5 P.M. EDT.
The Hepatitis B Vaccine
About the Vaccine
The hepatitis B vaccine was first licensed for use in the U.S. in 1981 and recommended for people who were considered “high-risk,” such as health care workers and men who have sex with men. Despite the introduction of the vaccine, overall infection rates did not change for the next several years, however.
“Initially the strategy used by the CDC was trying to vaccinate high-risk groups,” Asturias says. “That strategy failed miserably.”
CDC epidemiologists found that between 30 and 40 percent of people with hepatitis B had no risk factors. ACIP committee members convened in 1991 and recommended vaccinating all newborns or infants aged one month to two months old. In 2002 ACIP indicated a preference for the first dose to be given to all newborns before they came home from the hospital. These efforts “virtually eliminated the disease in children,” Offit says. From 1990 to 2019, cases of acute hepatitis B among children dropped by 99 percent.
About the Disease
The hepatitis B virus can spread through blood, semen and other body fluids of an infected person and is capable of lasting up to seven days on surfaces. Additionally, it can be passed from parent to child during pregnancy, childbirth or through close contact with bodily fluids after birth.
The virus attacks the liver, and people don’t often show symptoms until years later, when they either develop hepatitis (liver inflammation), cirrhosis (severe liver disease) or liver cancer. In rare cases, people can die from this disease.
What to Watch For
Kennedy has repeatedly cast doubt on the vaccine’s safety. His newly appointed ACIP members have questioned the need for the birth dose––and former senior CDC officials have hinted that the panel may vote to recommend delaying until age four.
Current ACIP chair Martin Kulldorff, who was handpicked by Kennedy, has questioned the timing of this vaccine. At the previous ACIP meeting in June, he said, “Unless the mother is hepatitis B positive, an argument could be made to delay the vaccine for this infection, which is primarily spread by sexual activity and intravenous drug use.”
Only 84 to 88 percent of pregnant women are screened for hepatitis B in the U.S., however, according to a 2019 report from the U.S. Preventative Services Task Force. Even if no one in the household is infected, infants could still be exposed, especially since more than 80 percent of people in the U.S. with hepatitis B do not know they have it, according to Mindie Nguyen, a hepatologist at Stanford Medicine.
“There’s no reason to wait” to vaccinate, she says. Infants who catch hepatitis B overwhelmingly become chronically infected, with no medical recourse. “Currently we have no cure for hepatitis B.”
Additionally, if the committee votes to delay the hepatitis B vaccine, then it might become more challenging for infants and children under four years old to access it.
“If you take away this birth dose of hepatitis B, which is there to prevent this infection early on, then we’ll see hepatitis B growing by the numbers over the years,” Asturias says. “But it may take us five to 10 years to see the impact of removing this birth dose.”
When to Watch
Hearings begin at 1:30 P.M. EDT on Thursday, with a vote on the vaccine itself and on its inclusion in the Vaccines for Children program scheduled for 5 P.M. EDT, after the committee votes on the MMRV vaccine.
The COVID Vaccines
About the Vaccines
This year, mRNA vaccines from Pfizer and Moderna and a protein-based vaccine from Novavax have been updated to protect against the most prevalent strains circulating in the U.S. It’s difficult to predict exactly how each year’s updated vaccine will perform against the strains that end up circulating, but last year’s vaccine reduced COVID-related urgent care and emergency room visit rates by about 33 percent among all adults compared with those who had not received an updated shot.
In recent years ACIP has voted to recommend updated COVID vaccines for everyone over the age of six months. During this year’s June meeting, the panel discussed COVID vaccines but did not hold a vote on them. In August, however, the Food and Drug Administration (FDA) authorized the vaccines only for people aged 65 years and older or with underlying health conditions that make them more vulnerable to severe infection.
About the Disease
COVID exploded onto the global scene as an entirely novel virus as 2019 turned to 2020. It has contributed to the deaths of more than 1.2 million people in the U.S. since its arrival. Even people who develop a mild infection are vulnerable to the lingering and sometimes debilitating constellation of symptoms dubbed long COVID.
What to Watch For
Although the ACIP agenda clearly flags the concerns the committee intends to discuss regarding the MMRV and hepatitis B vaccines, the situation is less clear for COVID. Presentations include epidemiology, effectiveness, safety and manufacturer updates. Some reports suggest that the administration is looking to further limit access by raising the age requirement for general access to 75 years old rather than 65.
To many experts’ alarm, ACIP discussions are widely expected to drum up concern surrounding rare adverse incidents reported in children after vaccination, including unvetted reports of 25 childhood deaths. Vaccines, like all medical interventions, can come with side effects, but these are carefully monitored and evaluated during trials and after a vaccine is rolled out. Scientists continually reevaluate safety data to determine whether potential risks merit changing existing vaccines—for example, the U.S. stopped using an oral polio vaccine that used a weakened live virus in 2000 because it occasionally triggered polio infection.
And ever since COVID vaccines rolled out, people and health care providers have been able to report issues to a government program called the Vaccine Adverse Event Reporting System, or VAERS. Reports in this system, including of childhood deaths and birth defects, are prompting antivaccine activists to lobby for the removal or restriction of COVID vaccines. But this is driven by a misunderstanding of what adverse events mean, Offit says.
“The VAERS system does not allow one to determine whether a vaccine caused a problem,” he says. “The best you can say about VAERS is that it raises a hypothesis.” Investigators must dig into each individual report to determine whether the unfortunate incident was actually caused by a vaccine or simply a coincidence. Offit fears any misrepresentation will push people away from COVID vaccines, particularly for small children.
This is deeply concerning, Asturias says, given that babies under one year old are just as likely to end up hospitalized from COVID as people between the ages of 65 and 75. “At six months, they have never seen COVID,” Asturias says. “There’s ample evidence that COVID in little babies, especially in their first year, if not the first two years, of life, is a disease that we should prevent.”
When to Watch
Hearings begin at 8:45 A.M. EDT on Friday, with a vote scheduled for 2:15 P.M. EDT.