title: Safety of vaccines used for routine immunization of U.S. children: a systematic review.
abstract: BACKGROUND
  Concerns about vaccine safety have led some parents to decline recommended vaccination of their children, leading to the resurgence of diseases. Reassurance of vaccine safety remains critical for population health. This study systematically reviewed the literature on the safety of routine vaccines recommended for children in the United States.
  
  
  METHODS
  Data sources included PubMed, Advisory Committee on Immunization Practices statements, package inserts, existing reviews, manufacturer information packets, and the 2011 Institute of Medicine consensus report on vaccine safety. We augmented the Institute of Medicine report with more recent studies and increased the scope to include more vaccines. Only studies that used active surveillance and had a control mechanism were included. Formulations not used in the United States were excluded. Adverse events and patient and vaccine characteristics were abstracted. Adverse event collection and reporting was evaluated by using the McHarm scale. We were unable to pool results. Strength of evidence was rated as high, moderate, low, or insufficient.
  
  
  RESULTS
  Of 20 478 titles identified, 67 were included. Strength of evidence was high for measles/mumps/rubella (MMR) vaccine and febrile seizures; the varicella vaccine was associated with complications in immunodeficient individuals. There is strong evidence that MMR vaccine is not associated with autism. There is moderate evidence that rotavirus vaccines are associated with intussusception. Limitations of the study include that the majority of studies did not investigate or identify risk factors for AEs; and the severity of AEs was inconsistently reported.
  
  
  CONCLUSIONS
  We found evidence that some vaccines are associated with serious AEs; however, these events are extremely rare and must be weighed against the protective benefits that vaccines provide.
authors.affiliation: RAND Corporation, Santa Monica, California; maglione@rand.org.
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Maglione
authors.affiliation: RAND Corporation, Santa Monica, California;
authors.forename: Lopamudra
authors.initials: L
authors.lastname: Das
authors.affiliation: RAND Corporation, Santa Monica, California;
authors.forename: Laura
authors.initials: L
authors.lastname: Raaen
authors.affiliation: RAND Corporation, Santa Monica, California;
authors.forename: Alexandria
authors.initials: A
authors.lastname: Smith
authors.affiliation: RAND Corporation, Santa Monica, California;
authors.forename: Ramya
authors.initials: R
authors.lastname: Chari
authors.affiliation: RAND Corporation, Santa Monica, California;
authors.forename: Sydne
authors.initials: S
authors.lastname: Newberry
authors.affiliation: RAND Corporation, Santa Monica, California;
authors.forename: Roberta
authors.initials: R
authors.lastname: Shanman
authors.affiliation: RAND Corporation, Santa Monica, California;
authors.forename: Tanja
authors.initials: T
authors.lastname: Perry
authors.affiliation: VA Greater Los Angeles Healthcare System and David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California; and.
authors.forename: Matthew Bidwell
authors.initials: MB
authors.lastname: Goetz
authors.affiliation: RAND Corporation, Santa Monica, California;Boston Children's Hospital, Boston, Massachusetts.
authors.forename: Courtney
authors.initials: C
authors.lastname: Gidengil
mesh_terms: D019433:Chickenpox Vaccine; D002648:Child; D006801:Humans; D007114:Immunization; D022542:Measles-Mumps-Rubella Vaccine; D061214:Patient Safety; D011159:Population Surveillance; D022243:Rotavirus Vaccines / Q000009:adverse effects; D014481:United States; D014612:Vaccines / Q000009:adverse effects*; D014761:Viral Hepatitis Vaccines / Q000009:adverse effects
chemical_list: D019433:Chickenpox Vaccine; D022542:Measles-Mumps-Rubella Vaccine; D022243:Rotavirus Vaccines; D014612:Vaccines; D014761:Viral Hepatitis Vaccines
keywords: evidence-based medicine; infectious disease; vaccine/immunization