The Advisory Committee on Immunization Practices (ACIP) cited concerns about febrile seizures for children under 4.

Over the course of a two-day meeting last week, the Advisory Committee on Immunization Practices (ACIP) voted to recommend against the combined measles, mumps, rubella, and varicella (MMRV) vaccine for children under the age of 4 due to concerns about febrile seizures.

https://www.lifesitenews.com/news/rfk-jr-immunization-committee-recommends-against-mmrv-vaccine-for-toddlers/?