Effectiveness of one dose of oral cholera vaccine in response to an outbreak: A case-cohort study

During a cholera outbreak in May 2015, in Juba, South Sudan, the Ministry of Health, Doctors Without Borders/Médecins Sans Frontières (MSF) and partners engaged in the first field deployment of a single dose of oral cholera vaccine to enhance the outbreak response. This is a case-cohort study, combining information on the vaccination status and disease outcomes from a random cohort recruited from throughout the city of Juba with that from all the cases detected. It was concluded that one dose of Shanchol was effective in preventing medically attended cholera in this study. These results support the use of a single-dose strategy in outbreaks in similar epidemiological settings.