title: Viral interference induced by live attenuated virus vaccine (OPV) can prevent otitis media.
abstract: BACKGROUND
  The goal of this study was to evaluate whether a live attenuated poliovirus vaccine (OPV) has clinically relevant interfering effect with non-polio infections causing otitis media in young children.
  
  
  METHODS
  Open trial in which the intervention group (64 children) received OPV at the age of 2, 3, 6 and 12 months. The control group (250 children) received IPV (inactivated polio vaccine) at the age of 6 and 12 months. Clinical symptoms were recorded by a questionnaire at the age of 3, 6, 12, 18 and 24 months.
  
  
  RESULTS
  Otitis media episodes were less frequent in the OPV than in the control group. A significant difference was seen at the age of 6-18 months (IRR=0.76 [95% CI 0.59-0.94], P=0.011) and was particularly clear among children, who attended daycare (IRR 0.37 [95% CI 0.19-0.71], P=0.003).
  
  
  CONCLUSIONS
  OPV provides some protection against otitis media. This effect may be mediated by viral interference with non-polio viruses.
authors.affiliation: Department of Virology, University of Tampere, Tampere, Finland. elina.m.seppala@uta.fi
authors.forename: Elina
authors.initials: E
authors.lastname: Seppälä
authors.forename: Hanna
authors.initials: H
authors.lastname: Viskari
authors.forename: Sanna
authors.initials: S
authors.lastname: Hoppu
authors.forename: Hanna
authors.initials: H
authors.lastname: Honkanen
authors.forename: Heini
authors.initials: H
authors.lastname: Huhtala
authors.forename: Olli
authors.initials: O
authors.lastname: Simell
authors.forename: Jorma
authors.initials: J
authors.lastname: Ilonen
authors.forename: Mikael
authors.initials: M
authors.lastname: Knip
authors.forename: Heikki
authors.initials: H
authors.lastname: Hyöty
mesh_terms: D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D010033:Otitis Media / Q000473:pathology / Q000517:prevention & control* / Q000821:virology*; D023321:Poliovirus Vaccines / Q000008:administration & dosage / Q000276:immunology*; D011795:Surveys and Questionnaires; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000276:immunology; D014762:Viral Interference
chemical_list: D023321:Poliovirus Vaccines; D014613:Vaccines, Attenuated; D015164:Vaccines, Inactivated