A modeling study estimated that the live-attenuated oral cholera vaccine Vaxchora (CVD 103-HgR) showed 87% effectiveness against cholera during the 2024 outbreak in Mayotte. Researchers analyzed real-world vaccination coverage and daily case data from a defined at-risk population. In the modeled community of 4,733 people considered at risk in Koungou, vaccination reached 71% coverage. Among 77 confirmed cases during the evaluation window, the model estimated vaccine prevented 87% of cholera cases at baseline, with a 95% credible interval of 74% to 99%. The analysis also tested assumptions through sensitivity analyses, reporting effectiveness range estimates from 75% to 91%. The study’s practical value for pharma and public health teams is demonstrating vaccine performance under time-sensitive outbreak conditions where challenge-study certainty is hard to replicate.