A key committee of the U.S. Centers for Disease Control and Prevention voted Thursday to alter its recommendation on an early childhood vaccine, after a discussion that at times pitted vaccine skeptics against the CDC’s own data.

After an 8-3 vote with one abstention, the CDC’s Advisory Committee on Immunization Practices will no longer recommend that children under the age of 4 receive a single-shot vaccine for mumps, measles, rubella and varicella (better known as chicken pox).

Instead, the CDC will recommend that children ages 12 to 15 months receive two separate shots at the same time: one for mumps, measles and rubella, or MMR, and one for varicella.

On Friday morning, the group decided unanimously to table an anticipated vote on changes to the hepatitis B vaccination schedule, after vaccine skeptics installed on the committee raised concerns that a proposal to delay the first dose by a month didn’t go far enough.

ACIP member Vicky Pebsworth, a nurse who serves as research director for the National Vaccine Information Center, an organization long criticized for promoting inaccurate vaccine information, challenged the previous day’s presentation by CDC staff on the vaccine’s safety.

She criticized the CDC for glossing over side effects such as fever, sleepiness and fussiness.

“These are not trivial reactions,” Pebsworth said. “I personally think we should be erring on the side of caution and adopt a more prudent vaccination policy.”

The group is slated to vote later Friday on changes to the COVID-19 vaccine.

The MMRV vote represents a relatively small change to current immunization practices. But doctors said the lack of expertise and vaccine skepticism on display during much of the discussion would only further dilute public trust in science and public health guidance.

“I think the primary goal of this meeting has already happened, and that was to sow distrust and instill fear among parents and families,” Dr. Sean O’Leary, chair of American Academy of Pediatrics’ Committee on Infectious Diseases, said Thursday during a news conference over Zoom.

“What we saw today at the meeting was really not a good-faith effort to craft immunization policy in the best interest of Americans. It was, frankly, an alarming attempt to undermine one of the most successful public health systems in the world,” O’Leary said. “This idea that our current vaccine policies are broken or need a radical overhaul is simply false.”

Giving the MMR and chickenpox vaccines in the same shot has been associated with a higher relative risk of brief seizures from high fevers in the days after vaccination for children under 4 — 8 in 10,000 children typically have febrile seizures after receiving the combination shot, compared with 4 in 10,000 who receive separate MMR and chickenpox shots at the same time.

Distressing as they are for family members to witness, seizures are a relatively common side effect for high fevers in young children and have not been associated with any long-term consequences, said Dr. Cody Meissner, a former pediatric infectious diseases chief at Tufts-New England Medical Center who is serving on ACIP for the second time (he previously served under Presidents George W. Bush and Obama).

The problem with splitting vaccines into multiple shots is that it typically leads to lower vaccine compliance, Meissner said. And the risks of not vaccinating are real.

“We are looking at a risk-benefit of febrile seizures … as compared to falling below a 95% coverage rate for herd immunity, and the consequences of that are devastating, with pregnant women losing their babies, newborns dying and having congenital rubella syndromes,” said Dr. Joseph Hibbeln, a psychiatrist and neuroscientist and another current ACIP member.

Meissner, Hibbeln and Hilary Blackburn were the only three members to vote against the change.

The first day of the meeting ended with a vote regarding continued coverage of the MMRV shot under the CDC’s Vaccines for Children Program, a publicly funded service that provides immunizations to nearly half of the nation’s children. The program currently only covers shots that ACIP recommends.

As chair Martin Kulldorff called the vote, several committee members complained that they did not understand the proposal as it was written. Three abstained from the vote.

As the meeting broke up, members could be heard trying to clarify with one another what they had just voted for. The group recast the vote Friday, and elected to align VFC coverage with their recommendation. The combined shot will no longer be covered by the public program.

The committee spent much of its first day debating whether to delay the first dose of the hepatitis B vaccine, a shot typically given at birth, until the child is 1 month old. They will vote on the proposal Friday.

The medical reason for altering the hepatitis B schedule was less clear.

“What is the problem we’re addressing with the hepatitis B discussion? As far as I know, there hasn’t been a spate of adverse outcomes,” said pediatrician Dr. Amy Middleman, one of several people to raise the point during the discussion and public comment period.

Committee member Dr. Robert Malone replied that changing the recommendation for when children should get vaccinated for hepatitis B would improve Americans’ trust in public health messaging.

“A significant population of the United States has significant concerns about vaccine policy and about vaccine mandates, [particularly] the immediate provision of this vaccine at the time of birth,” Malone said. The issue, he said, “is not one of safety, but one of trust.”

Hepatitis B is often asymptomatic, and half of infected people don’t know they have it, according to the CDC. Up to 85% of babies born to infected mothers become infected themselves, and the risk of long-term hazards from the disease is higher the earlier the infection is acquired.

Infants infected with the hepatitis B virus in the first year of life have a 90% chance of developing chronic disease, and 25% of those who do will die from it, according to the the American Academy of Pediatrics.

Since the vaccine was introduced in 1991, infant hepatitis B infections have dropped by 95% in the U.S. Nearly 14,000 children acquired hepatitis B infections from 1990 to 2002, according to the CDC; today, new annual infections in children are close to zero.

This week’s two-day meeting is the second time the committee has met since Kennedy fired all 17 previous ACIP members in June, in what he described as a “clean sweep [that] is necessary to reestablish public confidence in vaccine science.”

The next day, he named seven new members to the committee, and added the last five earlier this week. The new members include doctors with relevant experience in pediatrics, immunology and public health, as well as several people who have been outspoken vaccine skeptics or been criticized for spreading medical misinformation.

They include Pebsworth, whose organization has a long history of sharing inaccurate and misleading information about vaccines, and Malone, a vaccinologist who contributed to early mRNA research but has since made a number of false and discredited assertions about flu and COVID-19 shots.

In some cases, the new ACIP members also lack medical or public health experience of any kind. Retsef Levi, for example, is a professor of operations management at MIT with no biomedical or clinical degree who has nonetheless been an outspoken critic of vaccines.

“Appointing members of anti-vaccine groups to policy-setting committees at the CDC and FDA elevates them from the fringe to the mainstream. They are not just at the table, which would be bad enough; they are in charge,” said Seth Kalichman, a University of Connecticut psychologist who has studied the vaccine information center’s role in spreading vaccine misinformation. “It’s a worst-case scenario.”

Though ACIP holds three public meetings per year, it typically works year-round, said Dr. Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia and a former ACIP member in the early 2000s.

New recommendations to the vaccine schedule are typically written before ACIP meetings in consultation with expert working groups that advise committee members year-round, Offit said. But in August, medical groups including the American Medical Assn., the American Academy of Pediatrics and the Infectious Diseases Society of America were told they were no longer invited to review scientific evidence and advise the committee in advance of the meeting.

That same month, Kennedy fired CDC Director Susan Monarez — who had been appointed to the position by President Trump and confirmed by the Senate. On Wednesday, Monarez told a Senate committee that Kennedy fired her in part because she refused to sign off on changes he planned to make to the vaccine schedule this month without seeing scientific evidence for them.

She did not specify during the hearing what those changes would be.

The ACIP’s recommendations become official only after the CDC director approves them. With Monarez out, that responsibility now goes to Health and Human Services Deputy Secretary Jim O’Neill, who is serving as the CDC’s acting director.

Asked by reporters Wednesday whether the U.S. public should trust any changes the ACIP recommends to the childhood immunization schedule, Sen. Bill Cassidy (R–La.) was blunt: “No.”

Cassidy chairs the Senate committee that oversees the Department of Health and Human Services, and cast the deciding vote for Kennedy’s nomination. Before running for office, Cassidy, a doctor and liver specialist, created a public-private partnership providing no-cost hepatitis B vaccinations for 36,000 Louisiana children.

He cast his vote after Kennedy privately pledged to Cassidy that he would maintain the CDC immunization schedule.

As public trust in the integrity of CDC guidelines wobbles, alternative sources for information have stepped up. Earlier this year, the American Academy of Pediatrics announced that it would publish its own evidence-based vaccination schedule that differs from the CDC’s on flu and COVID shots. And on Wednesday, Gov. Gavin Newsom signed a law giving California the power to establish its own immunization schedule, the same day the state partnered with Oregon and Washington to issue joint recommendations for COVID-19, flu and RSV vaccines.

On Tuesday, an association representing many U.S. health insurers announced that its members would continue to cover all vaccines recommended by the previous ACIP — regardless of what happened at Thursday’s meeting — through 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,” America’s Health Insurance Plans said in a statement. The group includes major insurers Aetna, Humana, Kaiser Permanente, Cigna and several Blue Cross and Blue Shield groups. UnitedHealthcare, the nation’s largest insurer, is not a member.

It’s unclear what will be covered after 2026.

After the Eaton and Palisades fires ripped through Los Angeles County, the vast majority of residents in and around the burn scars were concerned about the hazardous compounds from the smoke and ash lingering in their homes, water and soil, according to a new survey published Tuesday. Yet many felt they lacked the support to move back safely.

While more than 8 in 10 residents hoped to test their properties for contamination, only half of them could. And as fire survivors searched for information to protect their health, many distrusted the often conflicting messages from media, public health officials, academics and politicians.

Researchers studying post-fire environmental health as part of the university consortium Community Action Project LA surveyed over 1,200 residents around the Eaton and Palisades burn scars from April through June, including those with destroyed homes, standing homes in the burn area and homes downwind of the fires.

Eaton and Palisades fire survivors said the lasting damage to their soil, air and water caused anxiety, stress, or depression. On average, survivors in the Eaton burn area — which has more significant environmental contamination — worried more than those in the Palisades.

An independent survey conducted for the L.A. fire recovery nonprofit Department of Angels in June found that the environment — including debris removal and contamination — was the most pressing issue for people who moved back home and those still displaced, more than construction costs, insurance reimbursements or a lack of strong government leadership.

Soil was the biggest worry for Eaton-area respondents in the Community Action Project survey. The team had just started collecting responses in April when the Los Angeles County Department of Public Health announced the first comprehensive soil testing results for the burn scars.

About a third of samples taken within the fire perimeter and nearly half downwind had lead levels above the state’s stringent health standards, designed to protect the most vulnerable kids playing in the dirt. Scientists attribute this lead to the Eaton fire, and not other urban contamination because samples taken in a nearby area unaffected by the fire had far lower lead levels.

The county sampling came after The Times reported in February that the U.S. Army Corps of Engineers would break precedent and forgo soil testing and remediation in its cleanup efforts.

Three quarters of Eaton fire survivors and over two thirds of Palisades fire survivors expressed worry over the air in their homes. Through private testing, many in both burn areas have found contaminants on surfaces in their home, including lead — which can cause brain damage and lead to developmental and behavioral issues in kids — as well as arsenic and asbestos, known carcinogens.

Around the start of the survey period, two groups independently found widespread lead contamination on surfaces inside homes that were left standing — some exceeding 100 times the level the Environmental Protection Agency considers hazardous.

The majority of survivors also felt distress over the safety of their drinking water, although to a lesser extent. Water utilities in both burn areas found small amounts of benzene — which can be a product of the incomplete combustion of vegetation and wood, and a carcinogen — in their drinking water systems.

But, thanks to a fire-tested playbook created by researchers like Whelton and adopted by the California State Water Resources Control Board, utilities were quick to begin the formidable undertaking of repressurizing their damaged systems, testing for contamination and flushing them out.

All of the affected utilities had quickly implemented “do not drink” and “do not boil” water orders following the fires. The benzene levels they ultimately found paled in comparison to blazes like the Tubbs fire in Santa Rose and the Camp fire in Paradise.

The last utility to restore safe drinking water did so in May. Around the same time, independent scientists verified the utilities’ conclusion that the drinking water was safe.

As researchers neared the end of collecting survey responses, L.A. County Department of Public Health launched a free soil testing program for residents in and downwind of the Eaton burn area. By the start of September, the County had shared results from over 1,500 properties.

Yet, residents in the Palisades hoping to test their soil, and residents in both burn scars looking for reassurance the insides of their homes are safe, have generally had to find qualified testing services on their own and either pay for it themselves or battle with their insurance companies.

The survey also found that, amid conflicting recommendations and levels of alarm coming from the government, media and researchers, Palisades fire survivors trusted their local elected officials most. For many living in the foothills of the Santa Monica Mountains, L.A. City Councilmember Traci Park has become the face of recovery.

Survivors in the Altadena area — which has no city government because it is an unincorporated area — turned to academics and universities for guidance. They’ve had a lot of contact with researchers because the Community Action Project LA, which conducted the survey, routinely meets with residents in both fire areas to understand and address the health risks homeowners face. Other post-fire research efforts, including from USC and Harvard University, have done the same.

Social media and the national news media ranked lowest in trust.

A key vaccine advisory panel for the Centers for Disease Control and Prevention voted Friday to drop a decades-old recommendation to vaccinate all newborns against hepatitis B, the committee’s most controversial decision since its overhaul by Health and Human Services Secretary Robert F. Kennedy Jr. in June.

The Advisory Committee on Immunization Practices voted 8 to 3 to adopt “individual-based decision making” for the newborn hep B vaccine dose for babies born to women who test negative, as are more than 99% of babies born in the U.S.

The move was met with condemnation by physicians and public health officials, including some on the committee. The CDC has recommended the shot since 1991, resulting in a 99% decline in rates of chronic hepatitis B infections in children and teens.

“‘Do no harm’ is a moral imperative. We are doing harm by changing this wording,” said Dr. Cody Meissner, an expert in pediatric infectious diseases at Dartmouth-Hitchcock Medical Center, who cast one of the few dissenting votes.

“This has a great potential to cause harm, and I simply hope the committee will accept this responsibility when that harm is caused,” said fellow no-vote Dr. Joseph Hibbeln, a psychiatrist formerly with the National Institutes of Health.

The committee spent the rest of Friday discussing the childhood and adolescent vaccination schedule. Comments from invited speakers and some committee members suggested that further revisions to the nation’s inoculation practices could be in store.

“Cumulative risk across the entire childhood vaccine schedule [is] a risk for which we do not have adequate data,” said committee vice chair Dr. Robert Malone, who contributed to early mRNA research but has since made a number of false and discredited assertions about flu and COVID-19 shots. “The potential cumulative risk” of childhood vaccines, he said, was “the elephant in the room.”

While CDC subject-matter experts were excluded from the meeting’s agenda, its second day began with a presentation from Aaron Siri, a leading antivaccine lawyer who has previously worked as Kennedy’s personal attorney.

Following a presentation in which Siri urged the committee to “end mandates” and “de-politicize vaccines,” Meissner called the attorney’s comments “a terrible, terrible distortion of all the facts.”

“You know how to present the facts that are favorable to you or to your client,” he added. “But for you to come here and make these absolutely outrageous statements about safety, I think it’s a big disappointment to me, and I don’t think you should have been invited.”

On X, Sen. Bill Cassidy (R-La.) criticized Siri’s presence, saying, “Siri is a trial attorney who makes his living suing vaccine manufacturers. He is presenting as if an expert on childhood vaccines. The ACIP is totally discredited. They are not protecting children.”

Changing the decades-old hep B recommendation has been a long-standing goal for vaccine opponents.

A planned vote on the issue at the committee’s meeting in September was tabled after fierce disagreement among members. When the discussion resumed Thursday, it repeatedly devolved into shouting.

“We’re trying to evaluate a moving target,” said Hibbeln, one of the move’s strongest opponents, during the meeting.

Although a change in the current recommendation would not bar newborns from receiving the vaccine, Medicaid and other public insurance programs would no longer be required to cover it, putting a birth dose out of reach for millions of poor families and complicating access for many others.

Unlike most vaccine-preventable diseases, such as whooping cough and chickenpox, hepatitis B is typically asymptomatic, often spreading silently until midlife, when 1 in 4 infected people develop liver cancer or cirrhosis.

“It’s one of the cancers with the highest mortality in the U.S.,” said Dr. Su Wang, medical director of Viral Hepatitis Programs and the Center for Asian Health at the Cooperman Barnabas Medical Center in New Jersey, who lives with the disease. “The life expectancy we give people is six months on average.”

Opponents of the current vaccine guidance — among them, Kennedy, surgeon general nominee Casey Means and President Trump — characterize the virus as the result of high-risk “adult” behavior, including sex and IV drug use.

“Hepatitis B is sexually transmitted,” Trump said at a White House news conference in September. “There’s no reason to give a baby that’s almost just born hepatitis B.”

But experts say that’s not how most people get the disease.

“It’s primarily transmitted mother to child,” said Dr. Chari Cohen, president of the Hepatitis B Foundation.

A majority of infected mothers are immigrants — particularly from the Philippines, China and Vietnam — making birth-dose vaccination an urgent priority for many California families.

Los Angeles County has recorded only a single case of perinatal Hep B transmission in the last five years, thanks in part to universal vaccination, the county health department said.

For some administration officials and panel members, the disease’s prevalence in immigrant communities is a talking point.

“The elephant in the room is immigration — we have had years of illegal immigration, undocumented people coming from higher-endemicity countries,” said Dr. Evelyn Griffin, one of the panel’s most vocal proponents of the change.

“We have problems adults need to solve with our resources there, rather than asking babies to solve this problem for us,” she said.

Griffin and other opponents of the current vaccine schedule say inoculating everyone places an unfair burden on healthy newborns from nonimmigrant families whose mothers have either screened negative or have few risk factors for the disease.

But experts say the proposed alternative of universal prenatal testing and aggressive risk assessment is unrealistic in the current American healthcare system. Today, less than 85% of mothers are screened — a number experts say will fall sharply if health subsidies disappear and Medicaid enrollment is cut in coming months.

“Our previous risk-based vaccination strategy failed,” said Katrin Werner Perez of the Alliance for Aging Research. “Prior to the 1991 change to universal vaccination, nearly 20,000 babies and children were infected annually in the U.S.”

For babies exposed to the blood-borne virus in utero or during delivery, every minute the shot is delayed heightens the risk of transmission. That reality prompted American public health officials to bump the first dose from early childhood, when it was given in the 1980s, to the first 24 hours of life, a recommendation the CDC has maintained since 1991.

“[The vaccine] saved thousands, if not millions of lives just in the U.S.,” Cohen said. “There’s more safety and efficacy data on the hepatitis B vaccine than just about anything else we put into our bodies.”

Those who catch hepatitis as infants are far more likely than those who get it as adults to develop chronic and ultimately fatal infections, data show.

Because the virus can live on surfaces for up to a week, doctors and public health experts stress that babies can contract it even from seemingly trivial exposures. Caregivers might not know they have the disease, and are unlikely to be tested, making the birth dose more urgent, they said.

“Mom is not the only person around the baby,” said Wang, who told the panel on Thursday she likely acquired the disease from her grandparents. “There’s grandparents, caregivers, other young children. You’re basically leaving that baby vulnerable.”

Even a small cut from shared nail clippers risks infection, data show.

Kennedy and his allies on the panel counter that the vaccine is unnecessary for most infants, and that delaying it would offer parents the opportunity to participate in “shared clinical decision-making” about whether and when to vaccinate.

Still, the panel has so far struggled to coalesce around an alternative recommendation. A planned vote Thursday was tabled in part because proposed language remained in flux even as the meeting was underway.

“This is the third version of the questions that most of the ACIP have received in 72 hours,” Hibbeln said.

Hibbeln and Meissner were vocal opponents of a change to the birth-dose recommendation when it was first debated in September.

“We will be creating new doubts in the mind of the public that are not justified,” Meissner said.

Others said the move would not go far enough.

“I don’t see even where is the argument to vaccinate younger children at all that live in a normal environment,” panelist Dr. Retsef Levi said in September.

In addition to limiting public coverage for the vaccine, a change to the recommendation could also force privately insured parents to navigate layers of complex authorizations in order to access a birth dose, experts warned.

Many feared the decision could further stigmatize the shot in a moment when many parents are refusing it simply because the recommendation is under review.

“States and hospitals are reporting declines in hepatitis B vaccination,” said Kayla Inthabandith of the Center for Advancing Health Equity in Rural and Underserved Communities. “Even some mothers living with hepatitis B are refusing the birth dose, putting their own infants at the highest risk of infection.”

Moving the recommendation from the first day of life to the second month could lead to 1,400 new infections a year, experts warned.

“Any child who gets a hepatitis B infection because we change policy is one too many,” said Dr. Judith Shlay. “I want us to make sure we never have any child get hepatitis B infection.”