[Investigation of factors determining stability of BCG vaccine].Med Dosw Mikrobiol 1992; 44(3-4):137-44MD
This study was aimed at establishment of influence of a carrier-sodium glutamate and of changes introduced during the process of freeze-drying on survival of BCG bacilli during lyophilization, as well on thermostability and homogeneity of the vaccine and its immunogenicity. It was found that appropriate drying of the vaccine after freeze-drying performed in higher temperature influences favorably its thermostability. Concentration of the carrier is significantly influential for survival of bacilli during freeze-drying. Vaccine containing 1% of sodium glutamate was characterized by best thermostability, homogeneity and high survival of bacilli during freeze-drying. These parameters were keeping on a high level also one year after expiration date. It was shown that there exists a proportional dependence between immunogenicity of the vaccine measured indirectly by intensiveness of tuberculin allergization and number of live particles of BCG contained in vaccination dose.