Liposomal vaccine: influence of antigen association on the kinetics of the humoral response.

The kinetics of the primary and secondary humoral responses to either encapsulated or surface-linked bovine serum albumin have been compared by measuring the production of specific total immunoglobulin, IgG and IgM at various times postimmunization. From our data it can be concluded that surface linkage is the best way to induce a rapid, intense and prolonged response which, in contrast to that induced by encapsulated BSA, is characterized by a low IgG/IgM ratio. The results are discussed in relation to the possible routes followed by the antigen depending on its mode of association with liposomes in the initiation of the humoral response. Our results suggest that liposomal vaccine may be designed to activate specific pathways of the immune network preferentially.