[Attempts at obtaining a pentavalent vaccine against leptospirosis]

Obtained was a five-valent vaccine (Leptospira pomona, L. canicola, L. grippotyphosa, L. mitis, and L. icterohaemorrhagiae). It was found that storage at 4degreesC does not impair the immunogenicity of the vaccine in the course of one year. Three groups of rabbits were used to test its immunogenicity--group I, injected once, subcutaneously, with 1 cu. cm of the vaccine; group II, injected subcutaneously, twice, at an interval of 7 days, with 1 cu. cm of the vaccine each time; and group III, injected once, muscularly, with 1 cu. cm. The animals were kept under observation for twelve months. It was established that in the case of intramuscular treatment there were highest antibody titers in the blood serum persisting up to the twelfth month.