A revamped federal vaccine advisory panel, appointed under Health and Human Services Secretary Robert F. Kennedy Jr., voted Thursday to no longer recommend a combination vaccine that protects against measles, mumps, rubella, and chickenpox (MMRV) for children under 4 years old.
In an 8–3 vote, with one member abstaining, the CDC’s Advisory Committee on Immunization Practices (ACIP) advised that young children receive the varicella (chickenpox) vaccine separately from the MMR vaccine. The decision marks a shift from previous CDC guidance, which allowed parents to choose between the combo shot and separate doses.
Panel members cited concerns about a small but higher risk of fever-related seizures—known as febrile seizures—associated with the MMRV vaccine, compared to giving MMR and chickenpox vaccines separately. These seizures, while generally not harmful long-term, can be alarming for parents.
Dr. Cody Meissner, who voted in favor of keeping the combination vaccine option, acknowledged the emotional impact of febrile seizures but emphasized that the vaccine remains safe. “It’s a very frightening experience,” he said during the meeting.
The panel previously reviewed seizure data related to the MMRV vaccine in 2009 and concluded that either option was acceptable, though it leaned toward recommending separate shots for the first dose. New data presented Thursday showed that 85% of parents already opt for separate shots.
A second vote—on whether to apply the updated guidance to the federally funded Vaccines for Children (VFC) program—sparked debate. Some members worried it would create unequal vaccine recommendations for low-income families. Despite this, the panel again voted 8–3 against changing the VFC program’s current recommendation, meaning children in the program will still be offered the combination MMRV vaccine.
The ACIP also delayed a separate vote on hepatitis B vaccinations for newborns whose mothers are not infected with the virus. That vote is expected Friday.
The hepatitis B vaccine has long been part of the standard newborn immunization schedule. Meissner defended the current approach, calling it “absolutely safe” and questioning the benefit of delaying the first dose. However, committee member Vicky Pebsworth—research director at the National Vaccine Information Center, a group often criticized for promoting vaccine skepticism—argued that conclusions about the vaccine’s safety may be “premature.”
The panel’s decisions are not final until approved by CDC acting director Jim O’Neill. The Department of Health and Human Services said it would review the insurance implications before implementing any changes.
Historically, insurance providers have followed ACIP recommendations closely. America’s Health Insurance Plans, a leading industry trade group, announced it will continue covering all ACIP-recommended vaccines in place as of September 1, 2025—including updated COVID-19 and flu shots—at no cost to patients through the end of 2026.
