title: Oral Polio Vaccination and Hospital Admissions With Non-Polio Infections in Denmark: Nationwide Retrospective Cohort Study.
abstract: Background.  Live vaccines may have nonspecific beneficial effects on morbidity and mortality. This study examines whether children who had the live-attenuated oral polio vaccine (OPV) as the most recent vaccine had a different rate of admissions for infectious diseases than children with inactivated diphtheria-tetanus-pertussis-polio-Haemophilus influenzae type b vaccine (DTaP-IPV-Hib) or live measles-mumps-rubella vaccine (MMR) as their most recent vaccine. Methods.  A nationwide, register-based, retrospective cohort study of 137 403 Danish children born 1997-1999, who had received 3 doses of DTaP-IPV-Hib, were observed from 24 months (first OPV dose) to 36 months of age. Results.  Oral polio vaccine was associated with a lower rate of admissions with any type of non-polio infection compared with DTaP-IPV-Hib as most recent vaccine (adjusted incidence rate ratio [IRR], 0.85; 95% confidence interval [CI], .77-.95). The association was separately significant for admissions with lower respiratory infections (adjusted IRR, 0.73; 95% CI, .61-.87). The admission rates did not differ for OPV versus MMR. Conclusions.  Like MMR, OPV was associated with fewer admissions for lower respiratory infections than having DTaP-IPV-Hib as the most recent vaccination. Because OPV is now being phased-out globally, further studies of the potential beneficial nonspecific effects of OPV are warranted.
authors.affiliation: Research Center for Vitamins and Vaccines, Bandim Health Project, Statens Serum Institut.
authors.forename: Signe
authors.initials: S
authors.lastname: Sørup
authors.affiliation: Research Center for Vitamins and Vaccines, Bandim Health Project, Statens Serum Institut; The Child & Adolescent Clinic, Rigshospitalet.
authors.forename: Lone G
authors.initials: LG
authors.lastname: Stensballe
authors.affiliation: Department of Infectious Disease Epidemiology , Statens Serum Institut , Copenhagen , Denmark.
authors.forename: Tyra G
authors.initials: TG
authors.lastname: Krause
authors.affiliation: Research Center for Vitamins and Vaccines, Bandim Health Project, Statens Serum Institut; Bandim Health Project, Indepth Network, Bissau, Guinea-Bissau.
authors.forename: Peter
authors.initials: P
authors.lastname: Aaby
authors.affiliation: Research Center for Vitamins and Vaccines, Bandim Health Project, Statens Serum Institut; Bandim Health Project, Indepth Network, Bissau, Guinea-Bissau; OPEN, Institute of Clinical Research, University of Southern Denmark and Odense University Hospital.
authors.forename: Christine S
authors.initials: CS
authors.lastname: Benn
authors.affiliation: Research Center for Vitamins and Vaccines, Bandim Health Project, Statens Serum Institut; Bandim Health Project, Indepth Network, Bissau, Guinea-Bissau; OPEN, Institute of Clinical Research, University of Southern Denmark and Odense University Hospital.
authors.forename: Henrik
authors.initials: H
authors.lastname: Ravn
keywords: heterologous immunity; immunization; nonspecific effects; nontargeted effects; oral polio vaccination