SALIVARY ANTIBODY-RESPONSES IN RHESUS-MONKEYS IMMUNIZED WITH STREPTOCOCCUS-MUTANS BY THE ORAL, SUB-MUCOSAL OR SUBCUTANEOUS ROUTES

Antibodies in whole saliva were investigated in 43 rhesus monkeys which had been immunized subcutaneously (SC), submucosally (SM) or orally with Streptococcus mutans. All monkeys before immunization had detectable natural agglutinating activity against Strep. mutans which resided in the macromolecular fractions of saliva. Submucosal immunization with whole cells in Freund's incomplete adjuvant induced a significant increase in salivary agglutinating activity to whole organisms and haemagglutination of antigen-coated red cells, whereas SC immunization did not. SC immunization with pronased cell-wall preparations of Strep. mutans led to greater increases in agglutinating activity in saliva than immunization with whole cells. Immunization by the oral route, with bacteria in gelatin capsules, resulted in increases in salivary agglutinating activity lasting for 25-30 days. Secondary immunization resulted in a more rapid response, but again of about 25 days. Administration of Strep. mutans cells in the drinking water led to a salivary antibody response in both whole and parotid saliva within 28 days. Antibody titres fell to pre-immune levels within 42 days of cessation of antigen administration. Oral immunization appears to lead to a salivary antibody response of short duration and is therefore unlikely to be useful in the protection against dental caries. Chromatographic analysis revealed that the increased agglutinating activity in saliva following immunization was mainly due to antibodies of the IgA class. © 1979.