A multi-country retrospective analysis of the impact of reactive OCV campaigns

The global OCV stockpile was established to ensure timely availability of vaccines as part of effective cholera outbreak response. Since its inception, no comprehensive retrospective analysis of the impact of reactive OCV campaigns has been conducted. This review is timely as capacity to respond to the multiple concurrent outbreaks globally continues to be strained, in part due to OCV shortages. The project is a multi-organisation collaboration that includes several countries that have a high burden of cholera and a history of implementing reactive OCV campaigns. The analysis will use mathematical and statistical modelling to quantify the short- and long-term impact of previous reactive OCV campaigns on cholera transmission and persistence at the population level. Additionally, we will compare methods for estimating individual-level protection of OCV vaccination from routinely-collected surveillance data. Results from quantitative analyses will be used to propose guidelines for planning and implementing effective reactive OCV campaigns, which will be developed in collaboration with international and in-country stakeholders. This study will contribute to informing evidence-based criteria for the allocation of OCV in reactive campaigns and maximising their impact when doses are limited, and aims to improve national capacity to quickly implement effective OCV campaigns.