Assessment of vaccine wastage in South Sudan.

INTRODUCTION: vaccine utilization monitoring provides valuable information for practical forecasting and formulation of strategies to reduce avoidable wastage. This monitoring is weak at county and health facility levels in South Sudan. Lack of national wastage rates could result in inaccurate forecasting, leading to vaccine shortages or overstocking and expiration of vaccines at the subnational and service delivery points. As the country gears to introduce relatively expensive vaccines such as rotavirus and pneumococcal vaccines, a robust vaccine utilization monitoring system must be rolled out. This study provides the best possible estimates of vaccine wastage rates and the possible causes of the wastage. METHODS: we conducted the study in 45 conveniently sampled health facilities across 9 of the ten states in South Sudan. Vaccine consumption data was prospectively collected to estimate vaccine wastage and the reason for the wastage of each vaccine type. RESULTS: wastage of lyophilized vaccines, measles, and Bacillus Calmette-Guérin (BCG) ranged between 39.0-66.7% and 52.1-74.3%, respectively, mainly due to doses that were discarded 6 hours after the opening of the vial or at the end of the immunization session. Wastage of liquid vaccines Oral poliovirus vaccines (OPV), Penta, Inactivated polio vaccine (IPV), and Tetanus- diphtheria (Td) ranged between 24.4-49%, 15.5-43.4%, 25.3-57.9%, and 3.8-57.2%, respectively, mainly due to unusable VVM, expiry, unused doses at the end of outreach sessions, and vials without labels. CONCLUSION: wasted rates for all vaccines were higher than the indicative WHO wastage rates used in South Sudan to forecast national vaccine needs. Unopened vial wastage was high and needs immediate attention.

Measles outbreak investigation in Aweil East county, South Sudan.

During January 2018-June 2020, Aweil East confirmed five measles outbreaks. In March 2020, Aweil East reported twenty measles IgM+ cases. Before this outbreak, Aweil East had confirmed an outbreak in late November 2019. Even after conducting outbreak reactive vaccinations (ORV) in December 2019 and February 2020, measles spread was not interrupted. The nationally supported measles follow-up campaign (MFUC) conducted in late February 2020 was deferred in Aweil East because of the February ORV. We reviewed the measles data collected through passive and active surveillance. A matched case-control study was conducted to evaluate potential exposures. Face-to-face interviews with cases and controls using a semi-structured questionnaire were used to collect demographics, disease, and exposures related data. A total of 687 cases with eight deaths; attack and case fatality rate of 123/100,000 population and 1.16%, respectively. Among the cases, 51.8% were male, the median age was four years, and 59% of cases ≥9 months were unvaccinated. Eighty point six percent (80.6%) of cases reported after the February ORV were unvaccinated. The outbreak peaked in late March 2020. Unvaccinated persons had higher odds of getting measles (adjusted odds ratio (AOR)=8.569; 95% CI [1.41- 53.4], p=0.02). Non exposed persons had a lower odd of getting measles (AOR=0.114; 95% CI [0.02-0.61], p=0.011). During 2018-2019, the accumulated number of unvaccinated children (18,587) is more than a birth cohort of the county. Persistent low routine vaccination is the most critical driver of the measles outbreaks. Low-quality ORV and the intermediate population density are secondary drivers of the outbreaks.