Feasibility of a preventive mass vaccination campaign with two doses of oral cholera vaccine during a humanitarian emergency in South Sudan.

Background: As an adjunct to cholera prevention measures, WHO advises the use of oral cholera vaccine through mass vaccination campaigns in high-risk areas and for vulnerable population groups. We assessed the feasibility and acceptability of a mass vaccination campaign using 1) a predominantly fixed and 2) a mobile door-to-door strategy.

Methods: Vaccination included administration of two doses (given 2 weeks apart) of oral cholera vaccine to individuals older than 1 year of age, in four refugee camps: Jamam, Doro, Batil and Gendrassa, and the host population in Maban County, South Sudan, from December 2012 to February 2013.

Results: A total of 258 832 doses were administered to a population of 166 000 (126 000 refugees and 40 000 host population). The first round coverage for the refugees was above 84% for Doro, Jamam and Batil and 104% for Gendrassa. The second dose reached the same coverage as the first dose. For the host population, the coverage for the first dose was above 90% in Doro and Jamam and 53% in Gendrassa and Batil. For the second round, the coverage was above 79% in Doro and Jamam and above 70% in Batil and Gendrassa.

Conclusions: The vaccination of a large population in an emergency context proved to be feasible and acceptable and achieved high coverage. This is encouraging and is a way forward for reducing cholera related morbidity and mortality among vulnerable populations.