No Rise in Seizure Risk With MMRV Booster Shot
One-Shot Measles, Mumps, Rubella, Varicella OK for 4- to 6-Year-Olds
MMRV: Seizure Risk Very Small continued...
Klein tells WebMD that even if these vaccines were responsible for all fever-related convulsions that occurred during this time period, there would be only one such seizure for every 15,500 doses of MMRV and one seizure for every 18,000 two-shot doses administered.
The study will be published in the May issue of the journal Pediatrics.
“This is a very reassuring finding,” Klein says. “We didn’t really see any evidence of an increased risk for these seizures in this age group for either of these combinations.”
Febrile Seizures Usually Harmless
Fever-related convulsions, known medically as febrile seizures, can occur with any condition that causes a spike in temperature, including illnesses like ear infections and, rarely, vaccinations.
While they can be terrifying for parents, they usually have no lasting effects, says infectious disease specialist Bruce Hirsch, MD, of the North Shore University Hospital in Manhasset, N.Y.
“Febrile seizures can be very disturbing and scary in very young children, but they don’t lead to long-term problems and they are not associated with epilepsy,” he tells WebMD.
Hirsch agrees that the new study should reassure parents, especially given its large size.
“You rarely see a vaccine safety study with such large numbers,” he says. “This gives us the ability to understand what is happening with the MMRV vaccine in this age group with a high degree of certainty.”