After Lengthy Debate, ACIP Updates MMRV Recommendations, Postpones Hepatitis B Vote

After a lengthy meeting that ran over seven hours, the Advisory Committee on Immunization Practices (ACIP) voted to no longer recommend the combined measles, mumps, rubella and varicella (MMRV) vaccine as an option for children younger than 4.

The vote was 8-3 with one abstention.

The vote on updates to the hepatitis B vaccine schedule is scheduled to occur tomorrow after extensive discussion today and confusion over why this update was being considered. Many ACIP members and agency commentators expressed concern regarding the hepatitis B vote, which may change the recommendation from children should be vaccinated against hepatitis B at birth to vaccination when they are one month old.

ACIP is in the spotlight because HHS Secretary Robert Kennedy Jr.'s views questioning the safety and efficacy of vaccines. He dismissed previous members of ACIP and replaced them with his picks. Kennedy also ousted Susan Monarez, Ph.D., as director of the Centers for Disease Control and Prevention. Monarez testified before a Senate committee on Wednesday that she was pushed after Kennedy pressured her to go along with changes to the childhood vaccine schedule. The CDC director must approve ACIP's recommendations before they become official CDC recommendations. Kennedy replaced Monarez with Acting CDC Director Jim O'Neill.

The meeting, held today and tomorrow, is being streamed on the CDC’s YouTube channel.

One notable absence from today's session was the American Academy of Pediatrics (AAP), which drew criticism from ACIP member Cody Meissner, M.D., professor of pediatrics at Dartmouth Geisel School of Medicine.

“I think it’s a grave mistake for the American Academy of Pediatrics not to participate in these discussions,” he said. “I think what the AAP is doing is moving themselves to irrelevance and the importance of the AAP is going to wane if they refuse to participate.”

The morning session focused on the MMRV vaccine, with CDC officials, including Arjun Srinivasan, M.D., and John Su, M.D., reviewing the dramatic decline in disease burden following the introduction of MMR and varicella vaccines.

They shared that measles previously caused hundreds of deaths annually, mumps was the leading cause of viral encephalitis and rubella led to devastating birth defects. Measles, mumps and rubella (also known as German measles) still occur, partly because of declining vaccination rates, but the number of cases has decreased significantly because of vaccination.

The CDC recommends that children get vaccinated twice against measles, mumps, rubella and varicella, once starting at ages 12-15 months and a second time between ages 4 and 6. Children can be vaccinated at those two ages with either two shots, the measles, mumps and rubella (MMR) and a separate shot of the varicella vaccine, or they can get all four vaccines in the combined MMRV. Many public health experts favor combined shots because they tend to be associated with higher vaccination rates. Until today, the CDC recommended the two-shot approach for the first shot but left MMRV as an option. The ACIP vote would scratch the MMRV-as-an-option recommendation for the first dose.

Much of the discussion of the MMRV today focused on safety concerns and mainly on febrile seizures associated with the first dose.

“Studies have identified an increased risk for febrile seizures during dose one of MMRV as compared with dose one of MMR plus varicella only during the one to two weeks after vaccination,” Su shared.

The risk disappears in older children receiving the second dose. The committee ultimately voted that children under four receive MMR and varicella separately for the first dose, while combination use remains allowed and preferred for the second dose.

The new ACIP chair, Martin Kulldorff, Ph.D., a biostatistician, rebuffed the characterization of the Kennedy-appointed ACIP as as being antivaccine.

“The members of this ACIP committee are committed to reassuring the public and restoring public confidence by removing unnecessary risk and harms whenever possible. That is a provaccine agenda,” he said. “False accusations that we and other respectable vaccine scientists are unscientific and dangerous antivaxxers just add legitimacy to antivax positions.”

Jason Goldman, M.D., an internal medicine specialist and president of the American College of Physicians, cautioned that some proposed vaccine changes could limit parental choice.

“Taking away the choice of parents to have informed consent and do what they might want to do for the health benefit of their children. So I urge this committee not to change the recommendations if they truly want to give parents that choice.”

The afternoon was devoted to hepatitis B vaccine discussions.

Evelyn Griffin, M.D., an obstetrician-gynecologist from Baton Rouge and one of ACIP’s newest members, raised questions about the quality of the evidence.

“If any of the studies were designed to have safety as the primary endpoint, because I see a lot of immunogenicity studies, I was wondering if safety was the primary endpoint for any of (the studies),” she asked.

Only three of nine studies included safety as a primary focus. Griffin also questioned a study linking bronchopulmonary dysplasia with the vaccine, pointing out that the authors themselves cited “seven significant limitations.”

Several panelists cautioned against delaying the birth dose.

Vicky Pebsworth, Ph.D., research director with the National Vaccine Information Center, said that if the recommendation for neonatal administration of a hepatitis B vaccine is changed, “what will happen is that we will increase the risk of harm based on no evidence of benefit, because there will be fewer children who will get the full hepatitis B vaccine series.”

Anu Hosangadi, medical communications strategist of the Hepatitis B Foundation, also highlighted the vaccine’s long safety record.

“Since its introduction in 1982, over 1 billion doses have been administered globally, with decades of surveillance demonstrating its efficacy. The body of evidence is unmatched,” she said.