title: Cross-sectional serologic assessment of immunity to poliovirus infection in high-risk areas of northern India.
abstract: BACKGROUND
  The objectives of this survey were to assess the seroprevalence of antibodies to poliovirus types 1 and 3 and the impact of bivalent (types 1 and 3) oral poliovirus vaccine (bOPV) use in immunization campaigns in northern India.
  
  
  METHODS
  In August 2010, a 2-stage stratified cluster sampling method identified infants aged 6-7 months in high-risk blocks for wild poliovirus infection. Vaccination history, weight and length, and serum were collected to test for neutralizing antibodies to poliovirus types 1, 2, and 3.
  
  
  RESULTS
  Seroprevalences of antibodies to poliovirus types 1, 2, and 3 were 98% (95% confidence interval [CI], 97%-99%), 66% (95% CI, 62%-69%), and 77% (95% CI, 75%-79%), respectively, among 664 infants from Bihar and 616 infants from Uttar Pradesh. Infants had received a median of 3 bOPV doses and 2 monovalent type 1 OPV (mOPV1) doses through campaigns and 3 trivalent OPV (tOPV) doses through routine immunization. Among subjects with 0 tOPV doses, the seroprevalences of antibodies to type 3 were 50%, 77%, and 82% after 2, 3, and 4 bOPV doses, respectively. In multivariable analysis, malnutrition was associated with a lower seroprevalence of type 3 antibodies.
  
  
  CONCLUSIONS
  This study confirmed that replacing mOPV1 with bOPV in campaigns was successful in maintaining very high population immunity to type 1 poliovirus and substantially decreasing the immunity gap to type 3 poliovirus.
authors.affiliation: World Health Organization (India), National Polio Surveillance Project, New Delhi.
authors.forename: Sunil
authors.initials: S
authors.lastname: Bahl
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Concepción F
authors.initials: CF
authors.lastname: Estívariz
authors.affiliation: World Health Organization, Geneva, Switzerland.
authors.forename: Roland W
authors.initials: RW
authors.lastname: Sutter
authors.affiliation: World Health Organization (India), National Polio Surveillance Project, New Delhi.
authors.forename: Bidyut K
authors.initials: BK
authors.lastname: Sarkar
authors.affiliation: World Health Organization, Geneva, Switzerland.
authors.forename: Harish
authors.initials: H
authors.lastname: Verma
authors.affiliation: World Health Organization (India), National Polio Surveillance Project, New Delhi.
authors.forename: Vibhor
authors.initials: V
authors.lastname: Jain
authors.affiliation: World Health Organization (India), National Polio Surveillance Project, New Delhi.
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Agrawal
authors.affiliation: World Health Organization (India), National Polio Surveillance Project, New Delhi.
authors.forename: Mandeep
authors.initials: M
authors.lastname: Rathee
authors.affiliation: World Health Organization (India), National Polio Surveillance Project, New Delhi.
authors.forename: Hemant
authors.initials: H
authors.lastname: Shukla
authors.affiliation: World Health Organization (India), National Polio Surveillance Project, New Delhi.
authors.forename: Surendra K
authors.initials: SK
authors.lastname: Pathyarch
authors.affiliation: World Health Organization (India), National Polio Surveillance Project, New Delhi.
authors.forename: Raman
authors.initials: R
authors.lastname: Sethi
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Wannemuehler
authors.affiliation: World Health Organization (India), National Polio Surveillance Project, New Delhi.
authors.forename: Hamid
authors.initials: H
authors.lastname: Jafari
authors.affiliation: Enterovirus Research Center, Haffkine Institute, Mumbai, India.
authors.forename: Jagadish M
authors.initials: JM
authors.lastname: Deshpande
mesh_terms: D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011051:Poliomyelitis / Q000453:epidemiology* / Q000517:prevention & control*; D017955:Poliovirus / Q000276:immunology*; D023321:Poliovirus Vaccines / Q000008:administration & dosage / Q000276:immunology; D016036:Seroepidemiologic Studies; D014611:Vaccination / Q000379:methods
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D023321:Poliovirus Vaccines
keywords: bivalent oral poliovirus vaccine; immunization campaigns; monovalent oral poliovirus vaccine; oral poliovirus vaccine; poliovirus