[The immunobiology of M-proteins of Streptococcus pyogenes. III. Immunization of rhesus monkeys (Macaca mulatta)].

Rhesus monkeys were used for the examination of immunogenicity of various preparations of M-antigens of Streptococcus pyogenes, types 1, 12, and 19. The antigens were applied in various dosages, but always with alumniumhydroxide as adjuvant. The challenge infection was provided by the homologous type, in some cases by an additional heterologous type. After intravenous infection all the animals fell ill, as the high dose of infective agents led to poisoning. The majority of immunized animals, however, did not show an increase of antistreptolysin titers with the type 1-infections - a sign of the absence of any reproduction of the injected streptococci in the animal organism. This behaviour was also observed in animals where no protective antibodies (bactericidal and long-chain antibodies) were verified before the infection. The electrocardiographic findings also indicate the protective effect of M-protein vaccines. In all control animals changes were seen which indicated an acute myocarditis. Normal electrocardiograms were obtained from the monkeys which had been immunized and afterwards infected. The administration of antigen every two weeks over a period of one year did not lead to the occurrence of any visible allergy in the skin test. The lymphocyte transformation test showed an increased rate of transformation in some immunized and infected animals, but this is not type-specific.