title: Immunization Coverage Surveys and Linked Biomarker Serosurveys in Three Regions in Ethiopia.
abstract: OBJECTIVE
  Demographic and health surveys, immunization coverage surveys and administrative data often divergently estimate vaccination coverage, which hinders pinpointing districts where immunization services require strengthening. We assayed vaccination coverage in three regions in Ethiopia by coverage surveys and linked serosurveys.
  
  
  METHODS
  Households with children aged 12-23 (N = 300) or 6-8 months (N = 100) in each of three districts (woredas) were randomly selected for immunization coverage surveys (inspection of vaccination cards and immunization clinic records and maternal recall) and linked serosurveys. IgG-ELISA serologic biomarkers included tetanus antitoxin ≥ 0.15 IU/ml in toddlers (receipt of tetanus toxoid) and Haemophilus influenzae type b (Hib) anti-capsular titers ≥ 1.0 mcg/ml in infants (timely receipt of Hib vaccine).
  
  
  RESULTS
  Coverage surveys enrolled 1,181 children across three woredas; 1,023 (87%) also enrolled in linked serosurveys. Administrative data over-estimated coverage compared to surveys, while maternal recall was unreliable. Serologic biomarkers documented a hierarchy among the districts. Biomarker measurement in infants provided insight on timeliness of vaccination not deducible from toddler results.
  
  
  CONCLUSIONS
  Neither administrative projections, vaccination card or EPI register inspections, nor parental recall, substitute for objective serological biomarker measurement. Including infants in serosurveys informs on vaccination timeliness.
authors.affiliation: Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Travassos
authors.affiliation: Ethiopian Public Health Institute, Addis Ababa, Ethiopia.
authors.forename: Berhane
authors.initials: B
authors.lastname: Beyene
authors.affiliation: JSI Research & Training Institute Inc., Arlington, Virginia, United States of America.
authors.forename: Zenaw
authors.initials: Z
authors.lastname: Adam
authors.affiliation: Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: James D
authors.initials: JD
authors.lastname: Campbell
authors.affiliation: Department of Social Work, The Women's Hospital, Melbourne, Australia.
authors.forename: Nigisti
authors.initials: N
authors.lastname: Mulholland
authors.affiliation: Centre pour le Développement des Vaccins, Mali (CVD-Mali), Bamako, Mali.
authors.forename: Seydou S
authors.initials: SS
authors.lastname: Diarra
authors.affiliation: Ethiopian Public Health Institute, Addis Ababa, Ethiopia.
authors.forename: Tassew
authors.initials: T
authors.lastname: Kassa
authors.affiliation: JSI Research & Training Institute Inc., Arlington, Virginia, United States of America.
authors.forename: Lisa
authors.initials: L
authors.lastname: Oot
authors.affiliation: JSI Research & Training Institute Inc., Arlington, Virginia, United States of America.
authors.forename: Jenny
authors.initials: J
authors.lastname: Sequeira
authors.affiliation: Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Mardi
authors.initials: M
authors.lastname: Reymann
authors.affiliation: Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: William C
authors.initials: WC
authors.lastname: Blackwelder
authors.affiliation: Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Yukun
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Inna
authors.initials: I
authors.lastname: Ruslanova
authors.affiliation: Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Jaya
authors.initials: J
authors.lastname: Goswami
authors.affiliation: Centre pour le Développement des Vaccins, Mali (CVD-Mali), Bamako, Mali.
authors.forename: Samba O
authors.initials: SO
authors.lastname: Sow
authors.affiliation: Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Marcela F
authors.initials: MF
authors.lastname: Pasetti
authors.affiliation: JSI Research & Training Institute Inc., Arlington, Virginia, United States of America.
authors.forename: Robert
authors.initials: R
authors.lastname: Steinglass
authors.affiliation: Ethiopian Public Health Institute, Addis Ababa, Ethiopia.
authors.forename: Amha
authors.initials: A
authors.lastname: Kebede
authors.affiliation: Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Myron M
authors.initials: MM
authors.lastname: Levine
mesh_terms: D016667:Bacterial Capsules / Q000276:immunology; D015415:Biomarkers / Q000097:blood*; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000276:immunology; D005002:Ethiopia; D005260:Female; D018073:Haemophilus Vaccines / Q000276:immunology; D006306:Health Surveys / Q000379:methods; D006801:Humans; D007114:Immunization / Q000379:methods; D017589:Immunization Programs / Q000379:methods; D007115:Immunization Schedule; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007223:Infant; D008297:Male; D010290:Parents; D014611:Vaccination / Q000379:methods
chemical_list: D015415:Biomarkers; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D018073:Haemophilus Vaccines; C044237:Haemophilus influenzae type b polysaccharide vaccine; D007074:Immunoglobulin G