The vaccine was found to offer elicit 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 programmes. The vaccine was later modified so that it could also counter a new form of epidemic cholera that emerged in the 1990s.
The two trials reported in the Bulletin were carried out in Hanoi and involved about 144 adults aged between 17 and 25 years and about 103 children aged 1-12 years. The trials were conducted by scientists from Viet Nam, Sweden, the United States, the Republic of Korea, the International Vaccine Institute in South Korea and the World Health Organization in Switzerland.
All the participants were given two doses of either the locally-produced vaccine, its Swedish counterpart, or a placebo, with the doses separated by an interval of two weeks. The trial in children began only after the trial in adults showed no important side-effects.
In both studies, the participants were observed for 30 minutes after each
dose and were visited daily for three consecutive days to ascertain
symptoms. Interviews were also conducted
Contact: Gary Hart
World Health Organization