title: Influence of enteric infections on response to oral poliovirus vaccine: a systematic review and meta-analysis.
abstract: BACKGROUND
  The impaired immunogenicity of oral poliovirus vaccine (OPV) in low-income countries has been apparent since the early field trials of this vaccine. Infection with enteropathogens at the time of vaccination may contribute to this phenomenon. However, the relative influence of these infections on OPV performance remains uncertain.
  
  
  METHODS
  We conducted a systematic review to examine the impact of concurrent enteric infections on OPV response. Using random-effects models, we assessed the effects of nonpolio enteroviruses (NPEVs) and diarrhea on the odds of seroconversion and/or vaccine virus shedding.
  
  
  RESULTS
  We identified 25 trials in which OPV outcomes were compared according to the presence or absence of enteric infections, the majority of which (n = 17) reported only on NPEVs. Concurrent NPEVs significantly reduced the odds of per-dose seroconversion for type 1 poliovirus (odds ratio [OR] 0.44, 95% confidence interval 0.23-0.84), but not type 2 (OR 0.53 [0.19-1.46]) or type 3 (OR 0.56 [0.27-1.12]). A similar reduction, significant for type 1 poliovirus (OR 0.50 [0.28-0.89]), was observed in the odds of vaccine virus shedding among NPEV-infected individuals. Concurrent diarrhea significantly inhibited per-dose seroconversion overall (OR 0.61 [0.38-0.87]).
  
  
  CONCLUSIONS
  Our findings are consistent with an inhibitory effect of concurrent enteric infections on OPV response.
authors.affiliation: Department of Infectious Disease Epidemiology.
authors.forename: Edward P K
authors.initials: EP
authors.lastname: Parker
authors.affiliation: Department of Paediatrics, St Mary's Campus, Imperial College London, United Kingdom MRC Unit, The Gambia, Fajara.
authors.forename: Beate
authors.initials: B
authors.lastname: Kampmann
authors.affiliation: Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India.
authors.forename: Gagandeep
authors.initials: G
authors.lastname: Kang
authors.affiliation: Department of Infectious Disease Epidemiology.
authors.forename: Nicholas C
authors.initials: NC
authors.lastname: Grassly
mesh_terms: D003967:Diarrhea / Q000276:immunology; D004769:Enterovirus Infections / Q000276:immunology*; D006801:Humans; D017955:Poliovirus / Q000276:immunology / Q000502:physiology; D011055:Poliovirus Vaccine, Oral / Q000276:immunology / Q000494:pharmacology*; D017201:Virus Shedding / Q000276:immunology
chemical_list: D011055:Poliovirus Vaccine, Oral
keywords: diarrhea; enterovirus; immunogenicity; interference; oral poliovirus vaccine