title: Safety of combination vaccines: perception versus reality.
abstract: BACKGROUND
  Combination vaccines contain multiple antigens to protect against several diseases simultaneously and have simplified the delivery of childhood immunizations. Children are healthier today because of the use of combination vaccines, and the United States is benefiting from record low numbers of vaccine-preventable diseases. Despite obvious benefits, concerns and misconceptions exist regarding the safety and efficacy of combination vaccines.
  
  
  METHODS
  A review of the pediatric literature to dispel the common misperceptions and potential barriers to combining vaccines.
  
  
  RESULTS
  Assurance that combination vaccines approved by the United States Food and Drug Administration undergo extensive testing will help to alleviate concerns regarding safety and efficacy of combination vaccines. Food and Drug Administration standards are rigorous and require that combination vaccines be as safe and effective as each component of the vaccine administered separately. Combination vaccines have been available for >50 years, and lessons learned during this time are continuously applied to the development and use of new products.
  
  
  CONCLUSIONS
  Children will benefit from new combination vaccines because fewer injections will be required to protect against vaccine-preventable diseases, allowing for the introduction of new vaccines into the immunization schedule and prevention of additional diseases.
authors.affiliation: Institute for Vaccine Safety, The Johns Hopkins University, Baltimore, MD, USA. nhalsey@jhsph.edu
authors.forename: N A
authors.initials: NA
authors.lastname: Halsey
mesh_terms: D016907:Adverse Drug Reaction Reporting Systems; D001321:Autistic Disorder / Q000139:chemically induced; D002648:Child; D002675:Child, Preschool; D004890:Erythema / Q000139:chemically induced; D006801:Humans; D007115:Immunization Schedule; D007223:Infant; D007231:Infant, Newborn; D015212:Inflammatory Bowel Diseases / Q000139:chemically induced; D022542:Measles-Mumps-Rubella Vaccine / Q000009:adverse effects; D010372:Pediatrics; D012449:Safety; D014481:United States; D017778:Vaccines, Combined / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology
chemical_list: D022542:Measles-Mumps-Rubella Vaccine; D017778:Vaccines, Combined