Measles-mumps-rubella-varicella combination vaccine and the risk of febrile seizures Journal Article uri icon
Overview
abstract
  • OBJECTIVE: In February 2008, we alerted the Advisory Committee on Immunization Practices to preliminary evidence of a twofold increased risk of febrile seizures after the combination measles-mumps-rubella-varicella (MMRV) vaccine when compared with separate measles-mumps-rubella (MMR) and varicella vaccines. Now with data on twice as many vaccine recipients, our goal was to reexamine seizure risk after MMRV vaccine. METHODS: Using 2000-2008 Vaccine Safety Datalink data, we assessed seizures and fever visits among children aged 12 to 23 months after MMRV and separate MMR + varicella vaccines. We compared seizure risk after MMRV vaccine to that after MMR + varicella vaccines by using Poisson regression as well as with supplementary regressions that incorporated chart-review results and self-controlled analyses. RESULTS: MMRV vaccine recipients (83,107) were compared with recipients of MMR + varicella vaccines (376,354). Seizure and fever significantly clustered 7 to 10 days after vaccination with all measles-containing vaccines but not after varicella vaccination alone. Seizure risk during days 7 to 10 was higher after MMRV than after MMR + varicella vaccination (relative risk: 1.98 [95% confidence interval: 1.43-2.73]). Supplementary analyses yielded similar results. The excess risk for febrile seizures 7 to 10 days after MMRV compared with separate MMR + varicella vaccination was 4.3 per 10,000 doses (95% confidence interval: 2.6-5.6). CONCLUSIONS: Among 12- to 23-month-olds who received their first dose of measles-containing vaccine, fever and seizure were elevated 7 to 10 days after vaccination. Vaccination with MMRV results in 1 additional febrile seizure for every 2300 doses given instead of separate MMR + varicella vaccines. Providers who recommend MMRV should communicate to parents that it increases the risk of fever and seizure over that already associated with measles-containing vaccines.

  • Link to Article
    publication date
  • 2010
  • published in
  • Pediatrics  Journal
  • Research
    keywords
  • Age Distribution
  • Chickenpox Vaccine/administration & dosage/*adverse effects
  • Cohort Studies
  • Databases, Factual
  • Follow-Up Studies
  • Incidence
  • Infant
  • Measles-Mumps-Rubella Vaccine/administration & dosage/*adverse effects
  • Retrospective Studies
  • Seizures, Febrile/*chemically induced/*epidemiology/physiopathology
  • Severity of Illness Index
  • Sex Distribution
  • Vaccination/adverse effects/*methods
  • Vaccines, Combined/administration & dosage/adverse effects
  • Additional Document Info
    volume
  • 126
  • issue
  • 1