Optimizing vaccine allocation for cholera epidemics

Oral cholera vaccines (OCV), administered in two doses, have emerged recently as a powerful tool for short-term outbreak control. When resources are limited, single-dose vaccination has been used as a way to stretch the supply, however, previous studies have shown that a single dose of vaccine is less effective, and wanes faster. In addition, studies have shown reduced effectiveness of the OCV in children under five years old, who are disproportionally affected by cholera. Determining who, how, and when to vaccinate are pressing decisions that public health officials usually take during an unfolding epidemic, often resulting in a sub-optimal use of resources. We will use mathematical models paired with optimization algorithms to determine optimal vaccine allocation, thereby providing public health officials with an evidence-based rationale for vaccine distribution. Our specific aims are: 1) To construct data-driven mathematical models of cholera transmission, infection and vaccination. 2) To determine optimal vaccine allocation strategies. 3) To develop and disseminate a free, user-friendly, decision-making tool to inform public health officials, in real time, about the best use of limited OCV supplies. This research will benefit countries with scarce resources for which making the best use of each dose of vaccine is a top priority.