Intussusception and oral poliovirus vaccination: is there an association?

Oral rotavirus vaccine was voluntarily withdrawn from the market after studies observed an increased risk of intussusception within 2 weeks after immunization. Concern has been raised that other orally administered vaccines, such as oral poliovirus vaccine (OPV), may also be associated with intussusception. In this 1990-1998 case-control study, the authors examined the association between OPV and intussusception in the Washington State Medicaid population, evaluating receipt of OPV during the month prior to intussusception among 119 cases and 589 controls matched by date of birth. Analysis was conducted via matched conditional logistic regression, controlling for sex. Between 1990 and 1998, 119 children younger than age 2 years had a therapeutic enema, surgical reduction, or hospitalization for intussusception and had been enrolled in Medicaid for at least 1 month prior to their intussusception date. There was no significantly elevated risk of intussusception associated with receipt of OPV; 9.2% (11/119) of cases and 8.5% (50/589) of controls were given OPV 0-28 days prior to the case's intussusception date (odds ratio=1.1, 95% confidence interval: 0.5, 2.2). However, to address the hypothesis that risk of intussusception is related to receipt of a particular dose of OPV, a larger study would be required.