Evaluation of thermostability of lyophilized BCG vaccines by using an accelerated thermal degradation test]

The degree of thermal degradation of BCG vaccines prepared from various substrains, using a test evaluating number of viable particles of BCG was determined. Thermal degradation coefficient were established for particular vaccines in different temperatures and a prognosis time curve of 50% CFU titer loss was constructed. It was found, that polish vaccine does not differ essentially from danish and french vaccines in respect to thermostability. Japanese preparation showed higher stability in all temperatures tested as compared to above mentioned vaccines. It was shown that when based on presented figures, and using interpolation method, it is possible with a high degree of probability foresee a decrease of vaccine titer at optional temperature.