[The determination of the optimal inoculation dose of an oral cholera chemical bivalent vaccine in a controlled experiment].

276 volunteers aged 19 years and over were placed under observation in the course of the trial of oral cholera vaccine in tablets, containing choleragen toxoid, O-antigens of serovars Inaba and Ogawa and a number of Vibrio cholerae exoenzymes, for safety, reactogenic properties and immunological effectiveness. The vaccine was found to produce no reactions in a dose of 1-4 tablets; the administration of 3 tablets (300,000 binding units of the toxoid and 10,000 units of O-antigens, serovars Inaba and Ogawa) was shown to induce the most intensive synthesis of both antitoxins and vibriocidal antibodies in the blood sera of volunteers, as well as IgA coproantibodies. The oral vaccine was found to have an advantage over parenteral vaccines due to the absence of reactogenic properties and the formation of local immunity: coproantibodies appeared in 80% and 9% of the vaccinees respectively.