Washington: A clinical study has shown for the first time that an oral cholera vaccine (ShancholTM) provides sustained protection against cholera in humans for up to five years.
The study showed the vaccine had a protective efficacy of 65 percent over a five-year period.
The landmark study was a collaboration between scientists from the International Vaccine Institute (IVI) an international organization based in Seoul, and the National Institute of Cholera and Enteric Diseases, (NICED), an institute under the Indian Council of Medical Research (ICMR) of India's Ministry of Health and Family Welfare.
Cholera is a potentially deadly infectious disease that causes profuse, dehydrating diarrhoea in children and adults.
The oral cholera vaccine (OCV) contains strains of killed cholera bacteria that have been previously shown to be safe in humans and is administered through a two-dose regimen.
The vaccine was specifically developed for use in developing countries through a public-private partnership led by IVI with support from the Republic of Korea, Sweden, and the Bill and Melinda Gates Foundation.
The partnership involved Shantha Biotechnics (part of the Sanofi group) based in Hyderabad, India; VaBiotech, a state-owned vaccine manufacturer located in Hanoi, Vietnam; and the University of Gothenburg in Sweden.
The vaccine, which is produced by Shantha Biotechnics in India and licensed as Shanchol, was prequalified by the World Health Organization (WHO) in September 2011.
"The study results suggest that this vaccine will protect persons at risk of severe cholera for five years," Dr. Thomas F. Wierzba, Deputy Director General of Vaccine Development and Delivery at IVI and co-author of the study, said.
"With protection sustained for five years, we will be able to provide greater benefits to the poor at reduced costs," he said.
The study is published in the Lancet Infectious Diseases.