STRATEGIES FOR PRODUCTION OF A POTENTIAL CANDIDATE VACCINE FOR CHOLERA

First attempt at cholerae vaccination was made by Jaime Ferran in 1884 . Since then, a variety of strategies and methods have been evolved to create a safe, efficacious vaccine against cholerae. for the first fe w years emphasis was on the development of parenteral vaccines. Howeve r, as a result of accumulation of a tremendous amount of knowledge, no t only on Vibrio cholerae - the causative agent, but also on its inter action with the host, emphasis has shifted towards the development of oral vaccines. Two such vaccines, one killed, a whole cell/B subunit c ombination vaccine and the other a live attenuate one, have shown prom ise. The combination vaccine in its present state of development confe rs only a transient protection in young children,while the live attenu ated one produces adverse reaction. To combat these various strategies are being evolved. In one attempted, a potential candidate vaccine st rain has been constructed from a non-reactogenic clinical isolate of V . cholerae, which is devoid of all known major virulence genes and is also a good colonizer. In animal studies this construct has shown cons iderable promise. This review discusses the various strategies that ha ve been employed so far in the quest for an ideal cholera vaccine.