Effect of Vaccine Direct Delivery (VDD) on vaccine stockouts and vaccination cases
Presenter: Ryoko Sato
Co-authors: Aisha Giwa, Loveth Metiboba, Vivian Odezugo, Adam Thompson
Poster file: [download]
Objective Vaccine stockouts are prevalent in Africa. Despite the potential importance of this as a barrier to universal vaccination coverage, rigorous study looking at ways to reduce vaccine stockouts has been limited. We causally evaluate the effect of Vaccine Direct Delivery (VDD), an intervention to ensure the vaccine-stock availability at health facilities, on the reduction of stockouts in Bauchi state, Nigeria. Methods Employing the interrupted time-series method, we evaluate the change in the occurrence of vaccine stockouts before and after the introduction of VDD in July 2015. We use the health-facility level data, collected through the District Health Information Software 2 (DHIS2), for monthly information on stockouts and stock balance in all the health facilities in Nigeria. To validate the causal relationship between VDD and vaccine stockouts, we conduct two sets of robustness checks. First, we evaluate the effect of VDD on the stockouts of other commodities. Second, we compare the trend of the prevalence of vaccine stockouts among health facilities between Bauchi state where VDD was introduced, and another state (Adamawa state) where VDD was never introduced. Results After the introduction of VDD, vaccine stockouts in Bauchi state decreased by 9 percentage points on average, and they have been decreasing monthly by 0.4 percentage points more than pre-VDD. There was no change in the level of other stockouts. In Adamawa state, where VDD was never introduced, the prevalence of vaccine stockouts did not change over time. In Bauchi state after VDD introduction, the stock balance of target vaccines all increased but we did not observe an increase in the number of vaccinations carried out. Conclusions The VDD intervention resulted in a significant reduction of vaccine stockouts, but not an increase in the number of vaccinations performed. More effort should be channeled into creating a demand for vaccines.