Matias, Wilfredo R., Guillaume, Yodeline, Cene Augustin, Gertrude, Vissieres, Kenia, Ternier, Ralph, Slater, Damien M., Harris, Jason B., Franke, Molly F., and Ivers, Louise C.
• The World Health Organization recommends the use of oral cholera vaccines in cholera control efforts. • We conducted a case-control study of the cholera vaccine, Euvichol® in Haiti. • Two-dose Euvichol® vaccine effectiveness was 69%. • Euvichol® can serve as one component of comprehensive cholera control efforts. The World Health Organization recommends the use of oral cholera vaccine (OCV) in cholera control efforts. Euvichol®, pre-qualified in 2015, is the leading component of the Global OCV stockpile, but data on its field effectiveness are limited. To evaluate Euvichol® vaccine effectiveness (VE), we conducted a case-control study between September 2018 to March 2020 following an OCV campaign in November 2017 in Haiti. Cases were individuals with acute watery diarrhea. Stool samples were tested by culture and real-time polymerase chain reaction of the Vibrio cholerae ctxA gene. Cases were matched to four community controls without diarrhea by residence, enrollment time, age, and gender, and interviewed for sociodemographics, risk factors, and self-reported vaccination. Cholera cases were analyzed by conditional logistic regression in the VE study. Non-cholera diarrhea cases were analyzed in a bias-indicator study. We enrolled 15 cholera cases matched to 60 controls, and 63 non-cholera diarrhea cases matched to 249 controls. In the VE analysis, eight (53%) cases reported vaccination with any number of doses compared to 43 (72%) controls. Adjusted two-dose OCV VE was 69% (95% CI –71 to 94%). Between 10-27 months after vaccination, Euvichol® was effective and similar to Shanchol™, suggesting that it can serve as one component of multi-sectoral comprehensive cholera control. [ABSTRACT FROM AUTHOR]