OCV Administration in Kolkata India by IVI-NICED Cholera Team (2006)

Cholera is one of the most feared diseases and many people die of the disease each year. The disease was first noted by British troops near Jessore, India in 1817. By 1832, it had spread across Russia and Germany to England. [1] During this time, cholera was recognized as a European disease, [2] but with improvements in sanitation and the provision of safe drinking water, the disease was eliminated from  Europe.

The effectiveness of improved sanitation in stopping transmission of cholera shows that these improvements in infrastructure—if they could be accomplished universally—would finally eliminate cholera’s threat. Unfortunately, provision of modern sanitation has not been feasible for many countries, and cholera has continued its spread from Asia to Africa, Latin America, and recently to Haiti.

It is not necessary to wait for improved sanitation to control transmission of cholera; one additional, effective, and currently available intervention is vaccination.

A study conducted in Kolkata, India showed that the oral cholera vaccine (OCV) Shanchol offers 65 percent protection for at least 5 years [3], with significant herd protection [4].  This is noteworthy because sustained protection for 5 years by an OCV had not been previously shown. Moreover, the vaccine shows similar benefits for both children and adults. This tells us that by combining both direct and indirect effects of the vaccine, and achieving reasonably high coverage, we could reduce the risk of chorea for at least five years, even in areas where sanitation conditions are poor. 

Given our current understanding and available solutions to control cholera with vaccine, why does cholera continue to be a threat in developing countries? Do health officials believe that cholera is not a major health problem?  Do they believe that oral rehydration solution (ORS), which is now commonly available, has solved the problem?  Perhaps there is a belief that the logistical support to provide two doses of vaccine to all the people in a community is too difficult to manage. Is the vaccine too expensive or too difficult to obtain?  Or is there a need to better define how often the vaccine should be given, who is to be targeted, and how the vaccination program can be integrated with water and sanitation components?

Even with the licensure of this efficacious vaccine, there is still more work to find practical solutions for eliminating cholera. Unless we find these, cholera will remain a life-threatening problem throughout the globe.

¹Cholera comes to Britain: October 1831.

²Hamlin C. Cholera: The Biography. New York. Oxford University Press, 2009

³Bhattacharya et al. 5 year efficacy of a bivalent killed whole-cell oral cholera vaccine in Kolkata, India: a cluster-randomised, double-blind, placebo-controlled trial. Lancet Infect Dis 2013; 13: 1050–56

⁴Ali et al. Herd protection by a bivalent-killed-whole-cell oral cholera vaccine in the slums of Kolkata, India. Clinical Infectious Diseases 2013;56(8):1123-31.