A double-dose, low-cost oral cholera vaccine administered through routine government health services can substantially reduce hospitalisation and deaths from cholera in densely populated urban settings, finds a new study by icddr,b and published in The Lancet.
While oral cholera vaccines were previously shown to be effective in trial settings, this is the first study to prove their effectiveness and feasibility in a real-life situation. The findings lend support to the use of the vaccines in routine mass vaccination programmes to help to control cholera in endemic countries.
Dr. Firdausi Qadri, Director for Centre for Vaccine Sciences at icddr,b and the principal researcher says that ?our findings show that a routine oral cholera vaccination programme in cholera-endemic countries could substantially reduce the burden of disease and greatly contribute to cholera control efforts.
The study took a cluster-randomised trial approach where the participants were randomly assigned to one of three groups: those who received Shanchol vaccine, those who received Shanchol and an intervention that encouraged hand washing and drinking water treatment with chlorine, and those who received no intervention at all, the control group.
The results show that at 65% vaccination coverage level the incidence of severely dehydrating cholera was reduced by 37% in the overall study population,
irrespective of their vaccination status.
The incidence of cholera decreased by 45% in the group that received both vaccination and hand washing-water treatment intervention. For participants that received the full two doses of the vaccine, the rate of hospitalisation decreased by more than 50%. For individuals who were vaccinated, it was shown to confer 53% protection two years after the vaccine was administered, a finding consistent with previous field trials.
 Source: ICDDR,B