CDC Panel Restricts MMRV Shot for Young Children

Atlanta, September 19, 2025 - The Advisory Committee on Immunization Practices (ACIP) recommended Thursday that children under four should no longer receive the combined measles, mumps, rubella, and varicella (MMRV) vaccine for their first dose, advising separate MMR and varicella shots instead.

The vote comes after a systematic safety review found a slightly elevated risk of febrile seizures in 12-15-month-olds receiving the four-in-one injection. ACIP members argued that splitting the vaccines could improve overall safety without compromising immunization coverage.

Key Changes and Rationale

  • Vote outcome: ACIP approved the change by an 8-3 margin, with one abstention.
  • Safety concerns: Data indicate a small but measurable increase in seizure risk when all four antigens are administered together to toddlers.
  • Age-specific guidance: Separate MMR and varicella shots are now preferred for the first dose in children aged 12-47 months; MMRV remains an option for the second dose given at 4-6 years.

Next Steps and Implications

Healthcare providers will discuss the updated recommendations with parents, emphasizing informed choice. The CDC director or Health and Human Services secretary must formally adopt the ACIP vote before it appears in the official immunization schedule.

Insurance coverage typically follows CDC guidelines, meaning separate vaccines will be covered under routine pediatric immunizations once adopted. Pediatricians warn that additional injections may require extra clinic visits and could affect compliance.

Broader Context

  • ACIP’s vote is nonbinding until endorsed by CDC leadership, which is currently led by an acting director.
  • The panel also postponed a decision on hepatitis B vaccination timing, to be addressed in a later session.
  • The recommendation follows recent reshuffling of ACIP membership by HHS Secretary Robert F. Kennedy Jr., reflecting renewed scrutiny of established childhood vaccine schedules.

Parents and clinicians are encouraged to review the updated guidance once published on the CDC website and to weigh the benefits and risks of each vaccination option.