Since 2000, UNICEF has published annual country-, regional- and global-level estimates of 2-dose vitamin A supplementation (VAS) coverage, but had not developed a consistent time-series. We present the first attempt to develop this time-series and then look at trends in coverage.
UNICEF collects VAS coverage data each year, based on administrative reports from countries utilizing a standard reporting form. Data undergo a review process employing a rule-based systematic approach, following which semester-specific and two-dose VAS coverage estimates are produced for countries whose data clear the review process. We reviewed all previously submitted VAS coverage data to produce a consistent time-series for 82 program countries between 2000 and 2014.
In 2000 and 2014, two-dose VAS coverage estimates were produced for 53 (65%) and 61 (74%) countries respectively. Twenty-three countries had data each year between 2000 and 2014, representing over 65% of all children in priority countries. Trend analysis indicate that in 2000, just 30 per cent of target children were fully protected with two annual doses, rising to 70 per cent by 2014.
Administrative data demonstrate an impressive rise in two dose VAS coverage since 2000. However, additional work is needed on methods to address the missing years of data and ensure a consistent approach to the analysis of trends going forward.