Aims/hypothesis: Animal and human studies have implied that enterovirus infections may modulate the risk of islet autoimmunity and type 1 diabetes. We set out to assess whether serial administration of live oral poliovirus vaccine (OPV) in early life can influence the initiation of islet autoimmunity in a cohort of genetically predisposed children.

Methods: OPV was administered to 64 children and a further 251 children received inactivated poliovirus vaccine (IPV). The emergence of type 1 diabetes-associated autoantibodies in serum (autoantibodies to GAD, insulinoma-associated protein 2, insulin and islet cells) was monitored during prospective follow-up. Stool and serum samples were collected for enterovirus detection by RT-PCR.

Results: Administration of OPV increased enterovirus detected in stool samples from 11.3% to 38.9% (p < 0.001) during the first year of life. During the follow-up (median 11.0 years), at least one autoantibody was detected in 17.2% of children vaccinated with OPV and 19.1% with IPV (p = 0.723). At least two autoantibodies were observed in 3.1% and 6.8% of children, respectively (p = 0.384).

Conclusions/interpretation: Replication of attenuated poliovirus strains in gut mucosa is not associated with an increased risk of islet autoimmunity.