Preparation and laboratory testing of plain and aluminum hydroxide-adsorbed cholera vaccines used in a field trial in Indonesia.

TWO TYPES OF CHOLERA VACCINE WERE PREPARED: a plain vaccine and an aluminium hydroxide-adsorbed vaccine, by using the Inaba NIH 35A3 and Ogawa NIH 41 serotypes of Vibrio cholerae. For cultivation, a solid medium was used and the cultures were inactivated with 0.02% thiomersal and by heating for 1 hour at 56 degrees C. The final vibrio concentration of the vaccines was adjusted to 16 x 10(9) vibrios/ml (equal proportions of the two serotypes). The antigenicity of the vaccines was assessed by the active mouse protection test and by the antibody production test, i.e. by determinating the vibriocidal antibodies in the sera of immunized mice. The results of the active mouse protection test showed that the antigenicity of the Inaba and Ogawa components of both vaccines met the WHO Requirements. The antigenicity of the Inaba component of both vaccines was about the same. The antigenicity of the Ogawa component of the plain vaccine appeared to be somewhat higher than that of the adsorbed vaccine. In the antibody production test, the adsorbed vaccine elicited a higher and longer-lasting immune response than the plain vaccine.