[Characteristics of the anthrax vaccinal strain STI-1 preserved for 30 years in the form of lyophilized spores].

A study was made of the biological properties of the spore culture of anthrax vaccine strain STI-1 lyophilized in 1944 and kept for 30 years without any passages. This dry culture contained not less than 29% of live spores; the culture growth in the nutrient broth and on the agar medium was typical for the strain. Immunogenicity tested in experiments on guinea pigs and rabbits was not reduced and corresponded to that of the reference STI-1 vaccine.