title: The Effect of Oral Polio Vaccine at Birth on Infant Mortality: A Randomized Trial.
abstract: BACKGROUND
  Routine vaccines may have nonspecific effects on mortality. An observational study found that OPV given at birth (OPV0) was associated with increased male infant mortality. We investigated the effect of OPV0 on infant mortality in a randomized trial in Guinea-Bissau.
  
  
  METHODS
  A total of 7012 healthy normal-birth-weight neonates were randomized to BCG only (intervention group) or OPV0 with BCG (usual practice). All children were to receive OPV with pentavalent vaccine (diphtheria, tetanus, pertussis, Haemophilus influenzae type b, and hepatitis B) at 6, 10, and 14 weeks of age. Seven national OPV campaigns were also conducted during the trial period. Children were followed to age 12 months. We used Cox regression to calculate hazard ratios (HRs) for mortality.
  
  
  RESULTS
  The trial contradicted the original hypothesis about OPV0 increasing male infant mortality. Within 12 months, 73 children in the BCG + OPV group and 87 children in the BCG-only group died, all from infectious diseases. Comparing BCG + OPV0 vs BCG only, the HR was 0.83 (95% confidence interval [CI], .61-1.13): 0.72 (95% CI, .47-1.10) in boys and 0.97 (95% CI, .61-1.54) in girls. For children enrolled within the first 2 days of life, the HR for BCG + OPV0 vs BCG only was 0.58 (95% CI, .38-.90). From enrollment until the time of OPV campaigns, the HR was 0.68 (95% CI, .45-1.00), the beneficial effect being separately significant for males (0.55 [95% CI, .32-.95]).
  
  
  CONCLUSIONS
  This is the only randomized trial of the effect of OPV0 on mortality. OPV0 may be associated with nonspecific protection against infectious disease mortality, particularly when given early in life. There are reasons to monitor mortality when OPV is being phased out.
  
  
  BACKGROUND
  NCT00710983.
authors.affiliation: Research Center for Vitamins and Vaccines, Statens Serum Institut, Copenhagen Department of Pediatrics, Kolding Hospital/University of Southern Denmark, Kolding.
authors.forename: Najaaraq
authors.initials: N
authors.lastname: Lund
authors.affiliation: Research Center for Vitamins and Vaccines, Statens Serum Institut, Copenhagen.
authors.forename: Andreas
authors.initials: A
authors.lastname: Andersen
authors.affiliation: Bandim Health Project, Indepth Network, Bissau, Guinea-Bissau.
authors.forename: Anna Sofie K
authors.initials: AS
authors.lastname: Hansen
authors.affiliation: Bandim Health Project, Indepth Network, Bissau, Guinea-Bissau.
authors.forename: Frida S
authors.initials: FS
authors.lastname: Jepsen
authors.affiliation: Bandim Health Project, Indepth Network, Bissau, Guinea-Bissau.
authors.forename: Amarildo
authors.initials: A
authors.lastname: Barbosa
authors.affiliation: Bandim Health Project, Indepth Network, Bissau, Guinea-Bissau.
authors.forename: Sofie
authors.initials: S
authors.lastname: Biering-Sørensen
authors.affiliation: Bandim Health Project, Indepth Network, Bissau, Guinea-Bissau.
authors.forename: Amabelia
authors.initials: A
authors.lastname: Rodrigues
authors.affiliation: Research Center for Vitamins and Vaccines, Statens Serum Institut, Copenhagen Institute of Clinical Research, University of Southern Denmark/Odense University Hospital.
authors.forename: Henrik
authors.initials: H
authors.lastname: Ravn
authors.affiliation: Research Center for Vitamins and Vaccines, Statens Serum Institut, Copenhagen 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, Statens Serum Institut, Copenhagen Institute of Clinical Research, University of Southern Denmark/Odense University Hospital.
authors.forename: Christine Stabell
authors.initials: CS
authors.lastname: Benn
mesh_terms: D002675:Child, Preschool; D003141:Communicable Diseases / Q000401:mortality*; D005260:Female; D006169:Guinea-Bissau; D006801:Humans; D007223:Infant; D007226:Infant Mortality; D007231:Infant, Newborn; D008297:Male; D011055:Poliovirus Vaccine, Oral / Q000008:administration & dosage*; D016019:Survival Analysis
chemical_list: D011055:Poliovirus Vaccine, Oral
keywords: heterologous immunity; infant mortality; neonates; nonspecific effects; oral polio vaccine