Effectiveness of an oral cholera vaccine campaign to prevent clinically-significant cholera in Odisha State, India.

•A phase III, clinical trial conducted in Kolkata showed that Shanchol, an oral cholera vaccine, provides 65% protection against cholera over five years.•To test the usefulness of this vaccine when deployed by public health department personnel using local resources, we conducted a mass vaccination campaign in a rural cholera-endemic area of India.•At the end of two years, the vaccine was found to reduce cholera cases by 69%.•This study supports widespread use of Shanchol by local health departments in cholera-affected areas of India and other nations.