The proposed work is aimed at the elucidation of the role of subpopulation of lymphoid cells (thymus influenced T-cells and non-thymus influenced B-cells) in immunity to coccidioidomycosis. The research is further directed towards the manipulation of the immune response via chemical modifications of antigens, in order to augment the induction of the type of immune response which is most crucial in conferring immunity against this systemic fungal infection.