Confused by headlines about the measles vaccine and febrile seizures? You’re not alone. Last week, a CDC advisory panel voted to recommend against the combined MMRV vaccine for children under age 4 — a decision that has left many parents wondering what it means for their families.
To help cut through the noise, we turned again to Dr. Mary Fairchok, a local board-certified pediatrician and pediatric infectious disease specialist at Mary Bridge Children’s Hospital. You may remember her from Seattle’s Child’s measles Q&A this summer, where she fact-checked common myths and gave parents straightforward guidance. Here, she explains what the new CDC recommendations do (and don’t) change, what parents should know about febrile seizures and the MMR vaccine, and why the American Academy of Pediatrics strongly disagrees with the panel’s vote.
Seattle’s Child: What is the MMRV vaccine, and what were the reasons for recommending it?
Dr. Fairchok: The MMRV vaccine (ProQuad by Merck) is a combination vaccine that protects against measles, mumps, rubella, and varicella (chickenpox). It was licensed in 2005 to improve adherence to the vaccination schedule by reducing the number of injections children receive. Previously, the only option was to give two separate injections to vaccinate against these diseases: MMR vaccine and varicella vaccine.
What did the CDC’s vaccine advisory committee (ACIP) recommend?
In September 2025, ACIP voted 8–3 to recommend that children under 4 years old receive separate MMR and varicella vaccines rather than the combined MMRV vaccine for their first dose.
What was their reasoning and does the AAP agree?
ACIP cited a slightly increased risk of febrile seizures in children aged 12–23 months who receive the MMRV vaccine compared to separate doses.
However, the American Academy of Pediatrics (AAP) strongly disagreed with the recommendation, stating it was based on outdated concerns and misrepresented data. Pediatricians were already well-aware of this slight risk and have been using shared decision-making with parents to allow them to decide if they preferred the MMRV versus separate injections at this age. This new recommendation from ACIP removes parental choice.
The AAP continues to support giving families the choice between MMRV and separate vaccines.
Are pediatricians still allowed to give MMRV? Why or why not?
Yes, pediatricians can still safely administer MMRV to children less than 4 years old, but it will not be covered under the Vaccines for Children (VFC) program. MMRV can also still be given to children 4 years of age and older and it will be covered by VFC.
ACIP initially voted on Thursday, September 18, 2025, to continue covering the cost of MMRV for toddlers in VFC, but decided against it in a vote on September 19, 2025.
Parents can also still choose MMRV for children under age 4 to reduce the number of injections if they consider the slightly elevated risk of febrile seizure to be less of a concern than an increased number of injections. However, the less than 50% of children whose vaccines are paid through VFC would not be covered for this vaccine.
What are the risks with MMRV? How are these different from giving the MMR vaccine and chickenpox vaccines separately, but at the same time?
The main risk associated with MMRV is a slightly higher chance of febrile seizures — about one additional seizure per 2,300–2,600 children vaccinated under the age of 4 compared to separate MMR and varicella vaccines. The risk of febrile seizures with MMRV at 4 years or greater is essentially zero.
These seizures have no long-term harm and do not recur. This is an issue that has been thoroughly investigated, discussed, and reviewed multiple times in the past by previous ACIP committees. It is not new information and pediatricians were already informing parents of this slight risk so they could make an informed choice.
Recommended vaccines can actually work as a preventive measure for febrile seizures, since getting sick with MMR, chickenpox, or the flu can cause fevers that trigger these seizures.
What are febrile seizures and how common are they after vaccines?
Febrile seizures are convulsions usually triggered within the first few hours of a fever. They typically occur in children under 4 and are most common in children between 12 and 18 months old.
They affect 3–5% of all children, not just those vaccinated, and most are brief, lasting 1-2 minutes before the child returns to normal. Febrile seizures are considered to be benign and do not cause brain damage or epilepsy.
Parents are routinely counseled at first dose immunization appointments about this rare possibility, which can happen about 1-2 weeks after vaccination. After MMRV, the risk is very slightly elevated (stated above: about one additional seizure per 2,300–2,600 children vaccinated compared to separate MMR and varicella vaccines) but remains very low.
When are kids given the MMR and chickenpox vaccines? (How often and at what ages?)
According to the AAP, children typically receive:
- First dose of MMR and varicella at 12–15 months
- Second dose at 4–6 years.
- Doses should be given at least 4 weeks apart. The maximum age for use of MMRV is 12 years.
- Make sure to consult your family’s pediatrician about vaccine recommendations based on your child’s overall health, how to plan safely for special situations, and advise you about catch-up vaccinations.
When is acting CDC Director Jim O’Neill supposed to make a final decision on this recommendation?
The ACIP recommendations are pending final approval by Acting CDC Director Jim O’Neill. As of now, there is no publicly confirmed timeline for when he will make a decision.
For more pediatric guidance, check out our Q&A on safe use of Tylenol during pregnancy and early childhood.
