Risk factors and familial clustering for fever 7-10days after the first dose of measles vaccines

Vaccine. 2017 Mar 14;35(12):1615-1621. doi: 10.1016/j.vaccine.2017.02.013. Epub 2017 Feb 21.


Background: Seven to ten days after a first dose of a measles-containing vaccine (MCV; i.e., MMR or MMRV), children have elevated fever risk which can be associated with febrile seizures. This study investigated individual and familial factors associated with fever 7-10days after MCV.

Methods: Retrospective cohort study among children who were <36months of age at receipt of MCV in six sites of the Vaccine Safety Datalink from 1/1/2000 to 12/31/2012. We evaluated medically-attended clinic or emergency department visits with a code for fever 7-10days after any MCV ("MCV- associated"). We evaluated factors associated with MCV-associated fever using χ2 and multivariable logistic regression analyses.

Results: Among 946,806 children vaccinated with MCV, we identified 7480 (0.8%) MCV-associated fever visits. Compared with children without fever after MCV, children with MCV-associated fever were more likely to have received MMRV than MMR (OR 1.3 95% CI 1.2, 1.5), have had medically attended fever both following previous vaccines (OR 1.3 95% CI 1.1, 1.6) and at any other previous time (OR 1.7 95% CI 1.6, 1.8), have had at least 1 prior seizure (OR 2.2 95% CI 1.7, 2.7), and have had >3 medical visits within the 6months before MCV (OR 1.7 95% CI 1.6, 1.8). In families with multiple MCV-immunized children, after adjusting for healthcare seeking behavior care for fever, those whose siblings had MCV-associated fever were more likely to also have MCV-associated fever (OR 3.5 95% CI 2.5, 4.8).

Discussion: Children who received MMRV vaccine or who had prior medically-attended fevers and seizures during the first year of life had increased risk of fever after a first dose of measles vaccine. After adjusting for familial propensity to seek care, MCV-associated fever still clustered within families, suggesting a possible genetic basis for susceptibility to developing fever due to measles vaccines.

Keywords: Fever; Measles; Safety; Vaccine.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Child, Preschool
  • Cluster Analysis*
  • Family Health
  • Female
  • Fever / chemically induced*
  • Fever / epidemiology*
  • Humans
  • Infant
  • Male
  • Measles Vaccine / adverse effects*
  • Retrospective Studies
  • Risk Factors


  • Measles Vaccine