SAFETY OF MEASLES-CONTAINING VACCINES IN 1-YEAR-OLD CHILDREN

Sunday, 8th of February 2015

SAFETY OF MEASLES-CONTAINING VACCINES IN 1-YEAR-OLD CHILDREN

1. Nicola P. Klein, MD, PhD^a,
2. Edwin Lewis, MPH^a,
3. Bruce Fireman, MA^a,
4. Simon J. Hambidge, MD, PhD^b,
5. Allison Naleway, PhD^c,
6. Jennifer C. Nelson, PhD^d,
7. Edward A. Belongia, MD^e,
8. W. Katherine Yih, PhD, MPH^f,
9. James D. Nordin, MD, MPH^g,
10. Rulin C. Hechter, MD, PhD^h,
11. Eric Weintraub, MPHⁱ, and
12. Roger Baxter, MD^a

- Author Affiliations

1. ^aKaiser Permanente Vaccine Study Center, Oakland, California;
2. ^bKaiser Permanente Colorado Institute for Health Research, Denver and Department of Ambulatory Care Services, Denver Health, Denver, Colorado;
3. ^cThe Center for Health Research, Kaiser Permanente Northwest, Portland, Oregon;
4. ^dGroup Health Cooperative and the University of Washington, Seattle, Washington;
5. ^eCenter for Clinical Epidemiology & Population Health, Marshfield Clinic Research Foundation, Marshfield, Wisconsin;
6. ^fHarvard Pilgrim Health Care Institute, Boston, Massachusetts;
7. ^gHealthPartners Research Foundation, Minneapolis, Minnesota;
8. ^hResearch and Evaluation, Kaiser Permanente Southern California, Pasadena, California; and
9. ⁱImmunization Safety Office, Centers for Disease Control and Prevention, Atlanta, Georgia

Abstract below; full text is at http://pediatrics.aappublications.org/content/135/2/e321.full.pdf+html

BACKGROUND AND OBJECTIVES: All measles-containing vaccines are associated with several types of adverse events, including seizure, fever, and immune thrombocytopenia purpura (ITP). Because the measles-mumps-rubella-varicella (MMRV) vaccine compared with the separate measles-mumps-rubella (MMR) and varicella (MMR + V) vaccine increases a toddlers risk for febrile seizures, we investigated whether MMRV is riskier than MMR + V and whether either vaccine elevates the risk for additional safety outcomes.

METHODS: Study children were aged 12 to 23 months in the Vaccine Safety Datalink from 2000 to 2012. Nine study outcomes were investigated: 7 main outcomes (anaphylaxis, ITP, ataxia, arthritis, meningitis/encephalitis, acute disseminated encephalomyelitis, and Kawasaki disease), seizure, and fever. Comparing MMRV with MMR + V, relative risk was estimated by using stratified exact binomial tests. Secondary analyses examined post-MMRV or MMR + V risk versus comparison intervals; risk and comparison intervals were then contrasted for MMRV versus MMR+V.

RESULTS: We evaluated 123 200 MMRV and 584 987 MMR + V doses. Comparing MMRV with MMR + V, risks for the 7 main outcomes were not significantly different. Several outcomes had few or zero postvaccination events. Comparing risk versus comparison intervals, ITP risk was higher after MMRV (odds ratio [OR]: 11.3 [95% confidence interval (CI): 1.9 to 68.2]) and MMR + V (OR: 10 [95% CI: 4.5 to 22.5]) and ataxia risk was lower after both vaccines (MMRV OR: 0.8 [95% CI: 0.5 to 1]; MMR + V OR: 0.8 [95% CI: 0.7 to 0.9]). Compared with MMR + V, MMRV increased risk of seizure and fever 7 to 10 days after vaccination.

CONCLUSIONS: This study did not identify any new safety concerns comparing MMRV with MMR + V or after either the MMRV or the MMR + V vaccine. This study provides reassurance that these outcomes are unlikely after either vaccine. .

• Copyright © 2015 by the American Academy of Pediatrics

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This Article

1. Published online January 5, 2015 Pediatrics Vol. 135 No. 2 February 1, 2015
   pp. e321 -e329
   (doi: 10.1542/peds.2014-1822)