Efforts to expand cholera vaccine use more extensively in the public health arena are advancing in the wake of a major vaccine trial in India recently.

Cholera, an enteric infection, still kills an estimated 120,000 persons in the least developed countries each year. While provision of safe water and food, adequate sanitation, and improved hygiene are the major public health interventions to fight cholera, a safe, effective and affordable vaccine continues to be a potentially useful tool for cholera prevention and control. The IVI, in collaboration with the National Institute of Cholera and Enteric Diseases (NICED) in India, has undertaken a large phase III trial of the Vietnamese vaccine in the urban slums of Kolkata to determine its efficacy in a cholera-endemic population. The trial, which started in July, enrolled some 70,000 persons, and will follow them for the next three years to monitor the vaccine’s efficacy.

The cholera vaccine under study, which is produced by VaBiotech in Vietnam following technology transfer from Sweden, is affordable at an estimated cost of less than one US dollar per person in Vietnam. Studies have shown the vaccine to be safe and effective in other developing country settings as well.

The IVI has been coordinating an effort to transfer the technology of the vaccine’s production from Vietnam to India and Indonesia.  Transferring the technology will allow these cholera-endemic countries to produce their own vaccine which will help to expedite licensure, keep vaccination costs down and encourage development of technical expertise.

The Kolkata trial comes after the IVI worked with VaBiotech to reformulate the vaccine in order to ensure that it meets WHO standards. The IVI also developed serological tests for evaluating immune responses to this vaccine and transferred these tests to NICED, including training of key personnel.  The IVI continues to collaborate closely with NICED.

The IVI is also collaborating with producers in Vietnam and India to obtain licensure for production of the reformulated vaccine in their respective countries. IVI scientists worked with the Vietnamese on clinical trials of the vaccine in adults and children.  A trial of the vaccine in Sonla, Vietnam found the vaccine to be safe and immunogenic. With this data, the vaccine will soon be licensed in Vietnam.

“These clinical trials will provide the basis for licensure of the vaccine in Vietnam and India, and thus pave the way for its wider use in cholera-endemic populations in Asia,” said IVI Director-General Dr. John Clemens. The trial is supported by the Diseases of the Most Impoverished (DOMI) and Cholera Vaccine Initiative (CHOVI) programs, funded by the Bill and Melinda Gates Foundation and Swedish International Development Cooperation Agency.