Abstract: The requirements for vaccines demand that they be safe and efficacious. The recommended storage temperature for vaccines is 2-8 degrees C, but their conditions of storage and transportation in the developing countries may frequently be far from ideal. This had led to the present study in which several vaccines have been stored at ambient temperature (+24 degrees C) and at +37 degrees C and their antigenic stabilities examined. Under these adverse conditions, typhoid, cholera and the components of DPT vaccines either in final containers or in bulk form have been shown to be stable for extended periods of time.

Abstract: 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.