Studies on the Mechanism of Action of Emulsified Vaccines,

Summary A model system in mice has been developed and defined, in which the adjuvant effect of emulsified vaccines was tested. Studies on the temporal relationship of enhanced antibody response to vaccination with adjuvant vaccine have shown that the initial peak level of antibody is dependent on repositing the virus in situ for about 16 days. Other data emphasizing the importance of the early events that take place after vaccination with adjuvant vaccine came from studies on the rate of breakdown of emulsified vaccines carried out by injection of P32 containing emulsions, by the removal of the site of inoculation and by irradiation designed to block further antibody production. These experiments have demonstrated that mineral oil emulsified vaccines tend to release a large and effective portion of their antigen soon after inoculation.