Immunization Coverage Surveys and Linked Biomarker Serosurveys in Three Regions in Ethiopia
Author: Travassos MA1, Beyene B2, Adam Z3, Campbell JD1, Mulholland N4, Diarra SS5, Kassa T2, Oot L3, Sequeira J3, Reymann M1, Blackwelder WC1, Wu Y1, Ruslanova I1, Goswami J1, Sow SO5, Pasetti MF1, Steinglass R3, Kebede A2, Levine MM1.
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). FINDINGS: 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. CONCLUSION: 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.
|Volume||2016 Mar 2;11(3):e0149970. doi: 10.1371/journal.pone.0149970. eCollection 2016.|
|Added on||28 April 2017 08:01:25|
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