Definition and use of “valid” district level vaccination coverage to monitor Global Vaccine Action Plan (GVAP) achievement: evidence for revisiting the district indicator

BACKGROUND: The Global Vaccine Action Plan (GVAP) Monitoring and Accountability Framework includes an indicator to reach 90% national vaccination coverage and 80% vaccination coverage in every district or equivalent administrative unit with three doses of diphtheria-tetanus-pertussis containing vaccines (DTP) across all 194 country signatories to GVAP by 2020. Assessment of progress against the district indicator component requires GVAP defined “valid” coverage. GVAP defines district coverage “valid” if the WHO and UNICEF estimate of national immunization coverage for DTP3 in the most recent year is 1) ≥90%, or 2) is identical to the reported national administrative coverage for DTP3 (regardless of coverage level). We draw attention to the potential disconnect that currently exists between GVAP vaccination coverage indicators and the practical capacity to monitor progress against those indicators. METHODS: We obtained national and aggregated district coverage data for the third dose of DTP containing vaccine (DTP3) for 194 countries for 2016 from publicly available databases maintained by the World Health Organization (WHO). We reviewed district line lists of coverage data for 96 countries for which district line lists of DTP3 coverage were available and categorized the district coverage values using the same groupings used by the GVAP Monitoring Framework. In doing so, we also tracked the number of districts with reported coverage >100%. RESULTS: In 2016, at least one district with DTP3 coverage value >100% was reported in the line lists of 76 of the 96 countries. Agreement in district coverage categories across each of five coverage groupings (<50%, 50-79%, 80-89%, 90-94%, ≥95%) was observed in 43 of the 96 countries. In 2016, 46 of 194 countries were classified as achieving both national DTP3 coverage ≥90% and DTP3 coverage ≥80% in every district, thereby achieving the GVAP target. Among these 46 countries, 22 countries reported district line-listing coverage data. We identified 10 of the 22 countries that reported at least one district with DTP3 coverage >100% ranging from 8% of districts in Sri Lanka to 97% of districts in Bangladesh. Seven countries reported at least 25% of the total districts had DTP3 coverage >100%. CONCLUSIONS: The observations of disparate district coverage from a subset of countries reporting district line lists of coverage data are a concern for the current GVAP approach ascribing the achievement of “valid” district coverage data. Our review of district line lists of coverage data does not support a current GVAP assumption that the district coverage values ≥80% fall between 80% and 100% (inclusive). We hope these results spur a review of the current approach to assess the GVAP coverage target of ≥90% national DTP3 coverage and ≥80% DTP3 coverage in all districts.