Researchers found a higher risk of febrile seizures 7 to 10 days after vaccination with Measles-Mumps-Rubella-Varicella combination vaccine (MMRV) compared to when MMR and varicella vaccines were given separately. Febrile seizures are seizures caused by a sudden spike in body temperature, and they are generally harmless.

According to the study, “Measles-Mumps-Rubella-Varicella Combination Vaccine and the Risk of Febrile Seizures,” published in the July 2010 print issue of Pediatrics (published online June 28), vaccination with MMRV resulted in one additional febrile seizure for every 2,300 doses given, compared to separate MMR plus varicella vaccines, but only in the 7 to 10 days following the vaccination. The researchers looked at Vaccine Safety Datalink information on more than 83,000 MMRV vaccine recipients and more than 376,000 MMR plus varicella vaccine recipients from 2000 to 2008. The children were 12 to 23 months old at the time of the vaccinations.

The American Academy of Pediatrics is an organization of 60,000 primary care pediatricians, pediatric medical subspecialists and pediatric surgical specialists dedicated to the health, safety and well-being of infants, children, adolescents and young adults. For more information, visit www.aap.org.