Studies on the Relationship between Leukopenia, Leukocytosis and Toxicity of Typhoid Chrome Vaccine

Abstract

Intravenous injection of typhoid vaccine immediately induces, as is known, leukopenia in the peripheral blood of rabbits, followed by leukocytosis in 6-10 hours. In these days however, no leukocytosis has been observed by the author following the injection of typhoid vaccine. It became known that this variation was caused by the use of typhoid chrome vaccine instead of formalin vaccine. Stimulated by this fact, the following experiments were carried out to study the cause of leukocytosis.
By the intravenous injection of 0.5-1.5 ml formalin vaccine pro kg of body weight to rabbits, the number of leukocytes decreased immediately in the peripheral blood, increased then gradually in 1-3 hours and markedly in 6-10 hours, to reach the count 3 times as great as that before the injection. However, the chrome vaccine i. e. formalin vaccine treated with 0.02% alum chrom. for 72 hours induced leukopenia, but no clear leukocytosis. Nevertheless, the chrome vaccine, when' heated 100°C for one hour brought about immediately leukopenia and in 9-12 hours a marked leukocytosis as did the contrast formalin vaccine.
Regarding the toxicity, the chrome vaccine proved much less toxic against the mice than the formalin vaccine. However, the chrome vaccine restored its toxicity by the heating at 100°C for one hour, showing almost the same mortality rate of rabbits as the formalin vaccine.
From these results it was concluded that the toxicity of typhoid vaccine was somehow related to the leukocytosis but not to the leukopenia.