title: Intussusception risk and disease prevention associated with rotavirus vaccines in Australia's National Immunization Program.
abstract: BACKGROUND
  Estimates of the risk of intussusception (IS) associated with currently licensed rotavirus vaccines (RV1 [Rotarix; GSK] and RV5 [RotaTeq; Merck]) diverge. Contemporaneous introduction of both vaccines in Australia enabled a population-based assessment of risk.
  
  
  METHODS
  Confirmed cases of IS in infants aged 1 to <12 months were identified from national hospitalization databases, supplemented by active hospital-based surveillance, from July 2007 through June 2010. Vaccination histories were verified by the Australian Childhood Immunisation Register, which was also used to identify age-matched controls. Self-controlled case series and case-control methods were used to assess the risk of IS associated with both vaccines in prespecified periods after vaccination. The estimated burden of vaccine-attributable IS was compared with estimated reductions in gastroenteritis hospitalizations.
  
  
  RESULTS
  Based on 306 confirmed cases of IS, the relative incidence of IS in the 1-7-day period after the first vaccine dose, was 6.8 (95% confidence interval, 2.4-19.0; P < .001) for RV1, and 9.9 (95% confidence interval, 3.7-26.4; P < .001) for RV5. There was a smaller increased risk 1-7 days after the second dose of each vaccine. The case-control analysis gave similar results. We estimate an excess of 14 IS cases and >6500 fewer gastroenteritis hospitalizations in young children annually in Australia after vaccine introduction.
  
  
  CONCLUSIONS
  We found a similarly increased risk of IS after both vaccines, but the balance of benefits and risks at population level was highly favorable, a finding likely to extend to other settings despite varying incidence of IS and potentially higher morbidity and mortality from both gastroenteritis and IS.
authors: Murdoch Children's Research Institute, Royal Children's Hospital.
authors: John B
authors: JB
authors: Carlin
authors: Kristine K
authors: KK
authors: Macartney
authors: Katherine J
authors: KJ
authors: Lee
authors: Helen E
authors: HE
authors: Quinn
authors: Jim
authors: J
authors: Buttery
authors: Ruth
authors: R
authors: Lopert
authors: Julie
authors: J
authors: Bines
authors: Peter B
authors: PB
authors: McIntyre
mesh_terms: D001315:Australia / Q000453:epidemiology; D016022:Case-Control Studies; D006801:Humans; D007223:Infant; D007443:Intussusception / Q000139:chemically induced* / Q000453:epidemiology; D012189:Retrospective Studies; D018570:Risk Assessment; D012400:Rotavirus Infections / Q000517:prevention & control*; D022243:Rotavirus Vaccines / Q000008:administration & dosage / Q000009:adverse effects*; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000009:adverse effects
chemical_list: C492457:RIX4414 vaccine; C492535:RotaTeq; D022243:Rotavirus Vaccines; D014613:Vaccines, Attenuated
keywords: intussusception; rotavirus vaccine; vaccination risk-benefit; vaccine adverse events; vaccine surveillance