Yellow fever vaccine fractional dose

Results for the immunogenicity date 28 days post-vaccination and safety data were reviewed by the study Data and Safety Monitoring Board (DSMB). The results were satisfactory opening the way to continue with the recruitment of 420 children in Mbarara, Uganda and 250 HIV infected adults in Kilifi, Kenya, to assess non-inferiority of the selected WHO prequalified vaccine (Chumakov Institute yellow fever vaccine).

2016, YF outbreaks occurred in Africa (Angola, Democratic Republic of Congo (DRC) and Uganda) as well as in South America (Brazil, Colombia and Peru). The stockpile of yellow fever vaccine was insufficient to protect all those at risk. The use of a fractional dose, 1/5^th of a full dose, was recommended by the World Organization. This recommendation is based on evidence from a limited number of clinical studies that such a reduced dose would provide adequate protection against the disease.  Epicentre is conducting a clinical study at its research center in Mbarara, Uganda and at  Medical Research Institute-Wellcome Trust Research Programme in Kilifi, Kenya. to broaden the evidence base on the use of a fractional dose, its safety, efficacy and a better insight in the duration of protection against disease. This information can then inform improved recommendations on the use of yellow fever vaccines in emergencies.