The improved low cost oral whole-cell (WC) cholera vaccine has been found to be safe and immunogenic in phase-III clinical trials among Indian children, as experts and policy makers feel that there is need for new-generation oral vaccine to check the spread of the disease in the country.

The phase-III trials and studies held by the National Institute of Cholera and Enteric Diseases (NICED) in Kolkata, a constituent of ICMR, in collaboration with the International Vaccine Institute, have found that the WC vaccine was safe and effective with children in the country. Besides, an economic analysis based on the Kolkata study also showed that WC vaccine was cost-effective and hence could emerge as an important tool to fight cholera, sources said.

This vaccine, improved version of what was developed in Vietnam earlier, meets international good manufacturing practice (GMP) and WHO standards for production and was licensed in India after studies in Kolkata and Vietnam showed the vaccine to be extremely safe and effective. The OCV has been licensed on February 24, 2009 by the Drugs Controller General of India.

Meanwhile, a recent meeting of the policy makers and experts from NICED, ICMR, Department of Biotechnology, International Vaccine Institute, Health Ministry, UNESCO, UNICEF, and WHO took stock of the situation, and called for new-generation oral cholera vaccines in the country.

The only WHO-pre-qualified OCV to date is the Swedish recombinant B-subunit killed whole-cell vaccine (rBS-WC), Dukoral. Vietnam has produced a cheaper variant of killed whole-cell vaccine devoid of the B subunit. This vaccine has been used in Vietnam's public health sector in high risk cholera areas and more than 9 million doses have been administered. However, an analysis of the Vietnamese vaccine showed that to comply with WHO guidelines, the vaccine needs to be reformulated and its production technology modified. The IVI worked with the Vietnamese producer, VaBiotech, to develop a killed whole cell cholera vaccine that meets quality standards. The Seoul, Korea-based international organization transferred the production technology to Shantha Biotechnics Ltd of India.

Cholera is one of the most dreaded diseases in the world, in some cases leading to death within 24 hours if left untreated. In 2007, WHO recorded 177,963 cholera cases and 4,031 deaths worldwide, while the actual number of cholera-related deaths is estimated to be as high as 120,000 each year. Cholera remains a serious problem in India, affecting most states, despite efforts to improve water, sanitation and case management. The states of West Bengal, Orissa, and the Delhi metropolitan area have the highest number of reported cholera cases in India.

According to Dr G B Nair, director, NICED, Kolkata, "A safe, effective, and affordable vaccine would be a useful tool for cholera prevention and control. After WHO discontinued the previous cholera vaccine about 30 years back, there has been only one vaccine available which however is costly and used mainly for travellers from industrialized countries moving to developing countries. Presently a vaccine has been developed which is effective, cheap, safe, produced by a reputed Indian company following WHO and international norms, which can be effectively implemented either pre-emptively in cholera prone areas or as reactionary measures for combating epidemics."