Studies on the optimal immunization schedule of experimental animals. V. The effects of the route of injection, the content of Mycobacteria in Freund's adjuvant and the emulsifying antigen.

The effects of several conditions for the immunization of mice was studied using an aliquot of a viomycin (VM) protein conjugate as the common primary or booster antigen. Responses of the mice were assessed by measuring mouse serum levels of total immunoglobulin G (IgG) and anti-VM antibody responses using the newly improved two assay methods. The choice of route was found to be a very important factor in immunization and intraperitoneal injection was the most optimal among the four routes studied. The effect of the concentration of Mycobacteria in Freund's complete adjuvant (FCA) was also studied, and it was found that a diluted FCA was more effective than a commercial FCA. The effect of the controlled release of the antigen was studied and three important phenomena were observed: The mice immunized by the mini-osmotic pump-aided controlled release of the antigen responded with similar small amounts of both total IgG and anti-VM antibody regardless of the presence or absence of FCA in the antigen; emulsifying the antigen with FCA was a very important condition for the effective elicitation of the specific antibody; a mixture of antigen and FCA without emulsifying produced little specific antibody and a large amount of total IgG. The more effectively immunized mice responded with a larger decrease in body weight soon after the primary injection.