Comparison of the effects of adjuvants and adjuvant doses on the quantitative and qualitative antibody response to selected antigens in New World squirrel monkeys Saimiri sciureus

The effect of several adjuvants and of adjuvant doses on the quantitative and qualitative antibody response to tetanus toxoid (TT) and a recombinant herpes simplex virus peptide (HSVgD) was evaluated in the New World monkey Saimiri sciureus. All adjuvant formulations were effective in inducing a strong antibody response to these antigens. The qualitative antibody response, as defined by monoclonal antibodies 3A2/G6 and 4G3/B5, was determined. Only 3A2/G6+ antibodies were induced after immunization with HSVgD irrespective of the adjuvant used and after immunization with TT alone. However, both types of antibodies were induced against TT in the presence of the adjuvants tested. These data suggest that both adjuvant and antigens can intervene in driving the quality of the antibody response induced after immunization. Strong antibody response to TT was induced at any adjuvant dose tested, suggesting that lower doses are as effective as higher doses. These findings can have implications on the design of future trials of vaccine candidate constructs in monkeys and eventually in human beings.