title: Cumulative and episodic vaccine aluminum exposure in a population-based cohort of young children.
abstract: BACKGROUND
  In addition to antigens, vaccines contain small amounts of preservatives, adjuvants, and residual substances from the manufacturing process. Some parents have concerns about the safety of these ingredients, yet no large epidemiological studies have specifically examined associations between health outcomes and vaccine ingredients, other than thimerosal. This study examined the extent to which the Vaccine Safety Datalink (VSD) could be used to study vaccine ingredient safety in children.
  
  
  METHODS
  Children born 2004-2011 were identified in VSD data. Using immunization records, two cohorts were identified: children who were up-to-date and children who were undervaccinated before age 2 years. A database was also created linking vaccine type and manufacturer with ingredient amounts documented in vaccine package inserts. Thirty-four ingredients in two or more infant vaccines were identified. However, only amounts (in mg) for aluminum were consistently documented and commonly contained in infant vaccines. Analyses compared vaccine aluminum exposure across cohorts and determined the statistical power for studying associations between aluminum exposure and hypothetical vaccine adverse events.
  
  
  RESULTS
  Among 408,608 children, mean cumulative vaccine aluminum exposure increased from 1.11 to 4.00 mg between ages 92-730 days. Up-to-date children were exposed to 11-26% more aluminum from vaccines than undervaccinated children. Power analyses demonstrated that safety studies of aluminum could detect relative risks ranging from 1.1 to 5.8 for a range of adverse event incidence.
  
  
  CONCLUSIONS
  The safety of vaccine aluminum exposure can be feasibly studied in the VSD. However, possible biological mechanisms and confounding variables would need to be considered before conducting any studies.
authors.affiliation: Institute for Health Research, Kaiser Permanente Colorado, 10065 E. Harvard Avenue, Denver, CO 80218, United States; Department of Epidemiology, University of Colorado School of Public Health, 13001 E. 17th Place, Campus Box B119, Aurora, CO 80045, United States. Electronic address: jason.m.glanz@kp.org.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Glanz
authors.affiliation: Institute for Health Research, Kaiser Permanente Colorado, 10065 E. Harvard Avenue, Denver, CO 80218, United States. Electronic address: sophia.r.newcomer@kp.org.
authors.forename: Sophia R
authors.initials: SR
authors.lastname: Newcomer
authors.affiliation: Institute for Health Research, Kaiser Permanente Colorado, 10065 E. Harvard Avenue, Denver, CO 80218, United States; Department of Pediatrics, University of Colorado School of Medicine, Children's Hospital CO, 13123 East 16th Avenue, Box 065, Aurora, CO 80045, United States. Electronic address: matthew.f.daley@kp.org.
authors.forename: Matthew F
authors.initials: MF
authors.lastname: Daley
authors.affiliation: Marshfield Clinic Research Foundation, 1000 North Oak Avenue, Marshfield, WI 54449, United States. Electronic address: dave_epi@hotmail.com.
authors.forename: David L
authors.initials: DL
authors.lastname: McClure
authors.affiliation: Kaiser Permanente Vaccine Study Center, Division of Research, Kaiser Permanente Division of Research, 2000 Broadway, Oakland, CA 94612, United States. Electronic address: roger.baxter@kp.org.
authors.forename: Roger P
authors.initials: RP
authors.lastname: Baxter
authors.affiliation: Group Health Research Institute, 1730 Minor Ave #1600, Seattle, WA 98101, United States. Electronic address: jackson.ml@ghc.org.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Jackson
authors.affiliation: Kaiser Permanente Center for Health Research, 3800 N Interstate Ave, Portland, OR 97227, United States. Electronic address: allison.naleway@kpchr.org.
authors.forename: Allison L
authors.initials: AL
authors.lastname: Naleway
authors.affiliation: Kaiser Permanente Department of Research and Evaluation, 100 S. Los Robles Ave, Pasadena, CA 91101, United States. Electronic address: marlene.m.lugg@kp.org.
authors.forename: Marlene M
authors.initials: MM
authors.lastname: Lugg
authors.affiliation: Immunization Safety Office, Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA 30333, United States. Electronic address: fxd1@cdc.gov.
authors.forename: Frank
authors.initials: F
authors.lastname: DeStefano
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage* / Q000009:adverse effects*; D000535:Aluminum / Q000008:administration & dosage* / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology* / Q000473:pathology; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D014612:Vaccines / Q000008:administration & dosage*
chemical_list: D000276:Adjuvants, Immunologic; D014612:Vaccines; D000535:Aluminum
keywords: Aluminum; Immunizations