Trials of a cholera vaccine manufactured in Viet Nam at a cost of about only US$.20 per dose have produced encouraging results, especially for children, according to the World Health Organisation (WHO). The vaccine elicited high levels of immunity in children for whom the risk of endemic cholera is highest, as well as in adults. These responses were comparable to those elicited by a Swedish-made vaccine that has already been licensed for use in several European countries.
Work began in Viet Nam during the mid-1980s on the production of a killed oral cholera whole-cell vaccine that could be used in the country's public health programme. The vaccine was later modified so that it could also counter a new form of epidemic cholera that emerged in the 1990s.
The researchers found that the Vietnamese vaccine was associated with no side effects and caused a better immune response in children than in adults, for reasons that were not clear. Further studies are needed in order to evaluate the clinical protection it confers.