title: Risk factors and familial clustering for fever 7-10days after the first dose of measles vaccines.
abstract: 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.
  
  
  
  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 χ2and multivariable logistic regression analyses.
  
  
  
  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).
  
  
  
  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.
authors.affiliation: Kaiser Permanente Vaccine Study Center, Oakland, CA, United States. Electronic address: Nicola.Klein@kp.org.
authors.forename: Nicola P
authors.initials: NP
authors.lastname: Klein
authors.affiliation: Kaiser Permanente Vaccine Study Center, Oakland, CA, United States.
authors.forename: Edwin
authors.initials: E
authors.lastname: Lewis
authors.affiliation: Kaiser Permanente Vaccine Study Center, Oakland, CA, United States.
authors.forename: Julia
authors.initials: J
authors.lastname: McDonald
authors.affiliation: Kaiser Permanente Vaccine Study Center, Oakland, CA, United States.
authors.forename: Bruce
authors.initials: B
authors.lastname: Fireman
authors.affiliation: The Center for Health Research, Kaiser Permanente Northwest, Portland, OR, United States.
authors.forename: Allison
authors.initials: A
authors.lastname: Naleway
authors.affiliation: Kaiser Permanente Colorado, Denver Health, Denver, CO, United States.
authors.forename: Jason
authors.initials: J
authors.lastname: Glanz
authors.affiliation: Group Health Research Institute, Seattle, WA, United States.
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Jackson
authors.affiliation: Center for Clinical Epidemiology & Population Health, Marshfield Clinic Research Foundation, Marshfield, WI, United States.
authors.forename: James G
authors.initials: JG
authors.lastname: Donahue
authors.affiliation: Research and Evaluation, Kaiser Permanente Southern California, Pasadena, CA, United States.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Jacobsen
authors.affiliation: Immunization Safety Office, Centers for Disease Control and Prevention, Atlanta, GA, United States.
authors.forename: Eric
authors.initials: E
authors.lastname: Weintraub
authors.affiliation: Kaiser Permanente Vaccine Study Center, Oakland, CA, United States.
authors.forename: Roger
authors.initials: R
authors.lastname: Baxter
mesh_terms: D002675:Child, Preschool; D016000:Cluster Analysis; D005192:Family Health; D005260:Female; D005334:Fever / Q000139:chemically induced* / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D008297:Male; D008458:Measles Vaccine / Q000009:adverse effects*; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D008458:Measles Vaccine
keywords: Fever; Measles; Safety; Vaccine