Measles-containing vaccines do not result in any significantly increased risk of febrile seizures in toddlers, a major analysis has found.
The study estimated the seizure rate in nearly 155,000 children aged four to six who had either the all-in-one measles-mumps-rubella and varicella vaccine (MMRV) or MMR and varicella separately (MMR+V).
Overall, seizures were rare throughout days 0 to 42, and there was no peak post-vaccination during days seven to 10 as reported in previous studies. There was one febrile seizure seven to 10 days after MMRV and none in the MMR+V group.
This equated to a risk of one febrile seizure per 15,500 doses of MMRV vaccine and one per 18,000 doses of MMR+V.
This finding was replicated when outpatient fever visits were analysed, with no peak seven to 10 days after vaccination and there were no significant differences in fever visits between the types of vaccine.
Study lead Dr Nicola Klein, a paediatrician in California, said: ‘This study provides reassurance that MMRV and MMR+V were not associated with increased risk of febrile seizures among four to six year-olds.'
Paediatrics 2012, online 2 April