Febrile seizures (fits induced by a high fever) are frightening and dramatic. A true febrile seizure is harmless and does not lead to epilepsy, but it can be very worrying for parents and caregivers, and these worries could stop children getting the vaccines they need. A study from the Kaiser Permanente Vaccine Study Center should provide reassurance--the seizures are not linked to measles-containing vaccines such as measles-mumps-rubella vaccine (MMR), with or without the varicella vaccine (V).
In the study published in Pediatrics, the researchers looked at the records of 4- to 6-year-olds from 2000 to 2008, and found children who had received a single MMRV vaccine, separate MMR and V vaccines on the same day, or MMR or varicella vaccines alone. The risks of seizures were very low, with one seizure between 7 and 10 days after the MMRV vaccine and none in the same period after the separate MMR and V vaccines.
"The results provide reassuring evidence that neither MMRV, nor MMR plus V, appear to be associated with an increased risk of post-vaccination febrile seizures in this 4-6 age group," said Dr. Nicola Klein, co-director of the Kaiser Permanente Vaccine Study Center.
Dr. Mark H. Sawyer, from the University of California-San Diego, said to Medscape Medical News: "There is no concern for giving either MMRV or MMR + varicella vaccine to [4- to 6-year-old] children. Many physicians may prefer to give MMRV because it is one less injection. Now they can do that without any concern about risk of febrile seizures. This gives both physicians and parents a choice to use whichever vaccines they prefer."
An earlier study has shown an increased risk of seizures in 1- to 2-year-olds when given MMRV vaccines compared with separate MMR and V vaccines. However, children are still more likely to have a seizure after a cold than after a vaccination.