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.”

After a contentious discussion that at times referenced discredited theories, low-quality data and desperate pleas from physicians and patients to rely upon sound science, a key CDC committee opted Friday to weaken its existing recommendations on COVID-19 shots, while punting other vaccine decisions to a later date.

The Advisory Committee on Immunization Practices voted unanimously to pull back its current unequivocal recommendation that all adults get vaccinated against COVID-19 in favor of a process of “shared clinical decision making,” in which patients are encouraged to speak to a doctor, nurse or pharmacist first.

The group came extremely close to recommending that the COVID-19 vaccine be available by prescription only, with a 6-6 vote broken by chair Martin Kulldorff’s “no” vote. The group also postponed a vote on hepatitis B vaccination indefinitely, with some members arguing that a proposal to delay the first dose did not go far enough.

The two-day meeting’s chaotic atmosphere left even many close observers confused about what decisions the group actually made.

“What we’re seeing is what happens when individuals who don’t have a basic understanding about how vaccines are delivered are making these crucial policy decisions for the American public. They don’t know what they’re doing,” Dr. Sean O’Leary, chair of American Academy of Pediatrics’ Committee on Infectious Diseases, said Friday during a news conference over Zoom. “What we are getting from ACIP is confusion.”

On Thursday, the committee voted that children under the age of four receive the measles, mumps and rubella (MMR) vaccine and the varicella, or chickenpox, vaccine in two separate shots given at the same time, instead of a single dose.

It was a relatively minor change. Many pediatricians already do this in order to reduce the risk of febrile seizures.

But the meeting’s tone and the decisions the committee appeared poised to make profoundly worried many physicians and public health officials.

“The damage isn’t just in today’s specific votes, it’s in legitimizing this framework where these laboratory-based studies and theories based on misrepresented findings are given equal standing with robust population-level safety data,” Dr. Jake Scott, an infectious disease specialist at Stanford University School of Medicine, said Friday. “Now every anti-vax group knows that they can package their claims and scientific-looking slides and cite some weird paper out of context, and then potentially get their concerns mandated into official medical documents.”

The COVID-19 discussion was led by Retsef Levi, a professor of operations management at MIT Sloan and the lone member of the committee with no biomedical or clinical degree.

He began the discussion by making clear that the committee would take into account anecdotal evidence and unpublished reports in its decision making, together with rigorously researched data.

“We need to leverage all the relevant published and unpublished scientific, clinical and public health data, information and knowledge, including experiences from the field. We are going to focus on personalized risk benefit analysis, and we’re going to very much stay away from the narratives or the statements about ‘safe and effective,’” said Levi, who has stated that mRNA vaccines are deadly and should be pulled from the market. “We don’t believe that these are appropriate or scientific language to talk about the issues related to vaccination.”

At one point, a microphone caught someone in the meeting muttering “idiot” as Levi was talking. It was not clear who the speaker was.

The group voted unanimously to postpone any changes to hepatitis B vaccination. Vaccine skeptics appointed to the committee said 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 information, criticized the CDC for glossing over side effects of hepatitis B vaccine 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.”

Hepatitis B has been nearly eliminated since the vaccine was introduced in 1991.

Up to 85% of babies born to infected mothers become infected themselves, and the risk of long-term effects from the disease is higher the earlier the infection is acquired.

Infants infected in the first year of life have a 90% chance of developing chronic hepatitis B and 25% of those who do will die from complications such as liver cancer and cirrhosis, according to the American Academy of Pediatrics.

Side effects from the vaccine are extremely rare, CDC scientists told the committee Thursday, and those that do occur tend to be mild.

Several committee members indicated they were unconvinced.

“There are gaps in what we know and understand about the effects of hepatitis B [vaccine], particularly on very young infants, and the conclusion that we know that it is safe is perhaps premature,” Pebsworth said.

At one point, she asked whether the irritability and fussing some babies showed at the time of the shot could be early symptoms of neurological problems stemming from the vaccine that hadn’t been studied.

At this, committee member Dr. Joseph Hibbeln pushed back.

“We have to vote on where there’s data of concrete harm or concrete benefit,” said Hibbeln, a psychiatrist who previously served as a section chief at the National Institutes of Health. “We’re going beyond data, and we’re turning into a discussion of speculation and possible clinical outcomes for which we have no data.”

The American Academy of Pediatrics said in a news conference Thursday that it would continue to recommend that infants receive their first hepatitis B shot at birth.

America’s Health Insurance Plans, an association that includes major U.S. insurers such as Aetna, Humana, Kaiser Permanente, Cigna and several Blue Cross and Blue Shield groups, announced this week that its members would continue to cover all vaccines recommended by the CDC as of Sept. 1 through the end of 2026.

For most of its 61-year history, ACIP meetings have been dry, technical affairs in which committees of experienced physicians, public health officials and research scientists get deep into the weeds of vaccine and disease data.

The committee’s role in vaccine insurance coverage and availability in the U.S. is paramount. Insurers are only required to cover vaccines the CDC endorses, though they can choose to cover others as well. The committee’s recommendation has typically set the vaccine schedule followed by schools and physicians. It also determines what vaccines are covered by the CDC’s Vaccines for Children Program, which pays to immunize nearly half the nation’s children.

Previously, the committee collaborated year-round with expert working groups like the American Medical Assn., the American Academy of Pediatrics and the Infectious Diseases Society of America to craft its recommendations and guidelines. Members also served staggered terms, so that new people coming on always joined colleagues with previous experience, and often went through more than a year of vetting.

But Kennedy fired the entire 17-member committee in June, and then informed medical groups they were no longer invited to review scientific evidence and advise the committee in advance of the meeting.

With the exception of Dr. Cody Meissner, who served on ACIP under presidents George W. Bush and Barack Obama, all of the members are new.

The lack of experience showed.

The group started the day by redoing a vote they’d hurriedly cast the previous afternoon on whether public funding would continue to cover the combined MMRV shot, as several members confessed to not fully understanding the text of the measure they’d voted on. In the new vote, they determined that it would not.

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

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.

“This committee has focused on poorly done research that supports their preconceived anti-vaccine notions, rather than trying to truly weigh risks and benefits to get to the best decisions for American kids,” said Dr. Adam Ratner, a New York City pediatric infectious disease specialist. “This ACIP meeting demonstrates a sad deterioration of our public health systems, and real families and children will suffer as a result.”

In one of the most comprehensive pictures yet of the growing health risks associated with wildfire smoke, new research suggests ash and soot from burning wildlands has caused more than 41,000 excess deaths annually from 2011 to 2020.

By 2050, as global warming makes large swaths of North America hotter and drier, the annual death toll from smoke could reach between 68,000 and 71,000, without stronger preventive and public health measures.

“The numbers are very big, and it definitely surprised us,” said Minghao Qiu, lead author and assistant professor at Stony Brook University. “We find that wildfire smoke is already killing a lot of people.”

During the 2020 wildfire season, the worst in California’s modern history, wildfires scorched more than 4.2 million acres statewide.

Many Californians, locked down during the COVID-19 pandemic, encountered choking air when they ventured outside. Bay Area residents remember the sickly orange sky they woke up to five years ago this month. The jet streams carried pollution thousands of miles east to the Atlantic Coast.

In the span studied, millions of people were exposed to unhealthful levels of air pollution. When inhaled, this microscopic pollution not only aggravates people’s lungs, it also enters the bloodstream, provoking inflammation that can induce heart attacks and stroke.

For years, researchers have struggled to quantify the danger the smoke poses. In the paper published in Nature, they report it’s far greater than public health officials may have recognized.

Yet most climate assessments “don’t often include wildfire smoke as a part of the climate-related damages. And it turns out, by our calculation, this is one of the most important climate impacts in the U.S.”

California, in particular, is projected to see the largest increase in smoke-related mortality, with over 5,000 excess deaths annually. The state’s vast forests and perennially dry climate make it the most fire-prone state in the nation. With 39 million residents, many Californians find themselves downwind.

The study also estimates a higher number of deaths than previous work in part because it projected mortality up to three years after a person has been exposed to wildfire smoke.

It also illustrates the dangers of smoke drifting from fire-prone regions into wetter parts of the country, a recent phenomenon that has garnered more attention with large Canadian wildfires contributing to hazy skies in the Midwest and East Coast in the last several years.

“Everybody is impacted across the U.S.,” Qui said. “Certainly the Western U.S. is more impacted. But the Eastern U.S. is by no means isolated from this problem.”

Elected officials and climate experts have called for reducing carbon emissions from burning fossils to prevent worsening effects from climate change. But because the concentration of greenhouse gases continues to climb each year and emissions are rising, not falling, some degree of warming is now unavoidable. Much of the carbon dioxide from a diesel tailpipe today, for example, will stay in the atmosphere for more than a century.

“Because of the inertia of the Earth’s [climate], even if we reduce the CO2 tomorrow, we are still going to see a considerable level of temperature increase,” Qiu said.

But that’s not to say nothing can be done. Qiu said it highlights the importance of adapting for a warmer planet, while working to reduce planet-warming emission.

Studies have shown air purifiers can drastically improve indoor air quality during wildfires. And states with a high fire risk, like California, should continue to fund prescribed burns, fires intentionally set by forestry professionals to clear away flammable vegetation and avoid larger wildfires.

“The tricky thing is, prescribed fires also generate smoke,” Qiu said. “So it’s going to be a trade-off. We are going to have some smoke, but the hope is it can reduce a much larger smoke burden due to [an actual] wildfire.”