MMRV does not increase the risk of seizure when it is given as the 2nd dose in the MMR immunization series, according to data from children in Australia. The study was published by Dr. Kristine Macartney in JAMA Pediatrics on August 14.
MMRV combines a vaccine against varicella (chickenpox) with vaccines against measles, mumps, and rubella. The MMR vaccine does not include the varicella component.
In the U.S., children typically get 2 doses of the MMR vaccine. The 1st dose of MMR is given at the age of 12 months and the 2nd dose is given at 4-6 years old.
The problem is that MMRV vaccines double a child’s risk of developing a very high fever that causes a seizure (called a febrile seizure) when it is given as the 1st dose in the MMR series.
The risk of having a seizure within 7-10 days is approximately 1 in 1,250 children who get an MMRV vaccine vs. approximately 1 in 2,500 children who get separate MMR vaccines and varicella vaccines, according to the Centers for Disease Control and Prevention (CDC).
These findings prompted the U.S. and Germany to stop recommending MMRV for the 1st dose in the MMR series. The CDC currently recommends caution when giving MMRV vaccines:
CDC recommends providers who choose to use the combination MMRV vaccine be aware of and clearly communicate to parents and caregivers the increased risk of fever and seizure within the 7 to 10 days following vaccination.”
The CDC also warns about an increased risk of seizures when flu shots are given at the same time as either the DTaP vaccine or the PCV13 (pneumococcal) vaccine in children under 2 years old.
The flu shot is not associated with an increased risk of febrile seizures when it was given on a different day from DTaP and PCV13. Furthermore, DTaP is only associated with seizures when it is given at the same time as a flu shot. There may be an increased risk of febrile seizures when the PCV13 (pneumococcal) vaccine is given by itself, according to the CDC.