Intussusception risk and disease prevention associated with rotavirus vaccines in Australia's National Immunization Program

Clin Infect Dis. 2013 Nov;57(10):1427-34. doi: 10.1093/cid/cit520. Epub 2013 Aug 26.

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.

Keywords: intussusception; rotavirus vaccine; vaccination risk-benefit; vaccine adverse events; vaccine surveillance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Australia / epidemiology
  • Case-Control Studies
  • Humans
  • Infant
  • Intussusception / chemically induced*
  • Intussusception / epidemiology
  • Retrospective Studies
  • Risk Assessment
  • Rotavirus Infections / prevention & control*
  • Rotavirus Vaccines / administration & dosage
  • Rotavirus Vaccines / adverse effects*
  • Vaccines, Attenuated / administration & dosage
  • Vaccines, Attenuated / adverse effects

Substances

  • RIX4414 vaccine
  • RotaTeq
  • Rotavirus Vaccines
  • Vaccines, Attenuated