An oral cholera vaccine was effective at reducing the incidence of severely dehydrating cholera and patient presentations of life-threatening cholera according to a cluster-randomized, open-label trial of residents of an urban endemic setting in Bangladesh.

The study’s participants were divided into 90 clusters of individuals targeted as being at high risk for contracting cholera. Patients in one-third of the clusters were offered Shanchol (Shantha Biotechnics–Sanofi ) vaccines. Patients in another third of the clusters were offered the Shanchol vaccine plus instructions and tools for improving hygiene. Patients in the final third of the clusters were not offered either intervention. The county’s government services administered the vaccine as two doses at an interval of at least 14 days. Of the 94,675 patients in the vaccination-only clusters, 65% got vaccinated. Similarly, 66% of the 92,539 patients in the vaccination plus hygienic improvements clusters received vaccinations.

Overall, the vaccine’s effectiveness at protecting against cholera was 37% in the vaccination group and 45% in the vaccination plus hygienic improvements group.

“Our findings show that a routine oral cholera vaccination program in cholera-endemic countries could substantially reduce the burden of disease and greatly contribute to cholera control effects,” said lead author Dr. Firdausi Qadri of the International Centre for Diarrhoeal Disease Research, Bangladesh, in a statement.

The research was funded by the Bill & Melinda Gates Foundation.

Read the full study in the Lancet .