MONDAY, April 2 (HealthDay News) -- Measles vaccines don't increase the risk of febrile seizures in children ages 4 to 6, according to a new study.

Febrile seizures are brief, fever-related convulsions that are not fatal and do not lead to brain damage, epilepsy or other seizure disorders.

The study, conducted by the Kaiser Permanente Vaccine Study Center and funded by the U.S. Centers for Disease Control and Prevention, looked at data from nearly 87,000 children ages 48 to 83 months who received the measles-mumps-rubella-chickenpox (MMRV) vaccine; the MMR vaccine plus the varicella vaccine for chickenpox, administered separately but on the same day; or either the MMR or varicella vaccine alone.

There was no increased risk of febrile seizures among the children during the six weeks after they received any of the vaccinations, according to the study, which appears in the current issue of the journal Pediatrics.

"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-to-6 age group," lead author Dr. Nicola Klein, co-director of the Kaiser Permanente Vaccine Study Center, said in a news release.

In the United States, children receive two doses of MMR and varicella vaccines. The first is given between ages 1 and 2 and the second between ages 4 and 6.

A previous study found that children ages 1 to 2 who received the MMRV vaccine were twice as likely to have a febrile seizure seven to 10 days after vaccination than those who received MMR plus V.

The researchers noted that febrile seizures typically occur in children ages 6 months to 5 years, and the incidence of these seizures peaks at about 18 months of age.

"As febrile seizures are generally much less likely to occur among 4- to 6-year-old children, it is not surprising that we did not detect increased febrile seizures following MMRV or MMR plus V among 4- to 6-year-olds," Klein said.

"Families of 4- to 6-year-olds can be reassured from this study that the combination MMRV vaccine is safe," said Dr. Bruce Hirsch, associate chairman for clinical services at North Shore University Hospital in Manhasset, N.Y.

"Febrile seizures are scary; the child develops a high fever and convulses," he said. "The condition is surprisingly common and can occur after colds and other viral infections."

More information

The U.S. National Institute of Neurological Disorders and Stroke has more about febrile seizures.