CD4 and infection: Vaccination with recombinant NH36 protein or DNA, protected mice from L. donovani (23), Leishmania major (24), L. infantum chagasi (25, 26), L. mexicana (25), and Leishmania amazonensis (12, 13) infections and also protected dogs infected with L. infantum chagasi through a Th1 immune response mediated by IFN-γ-producing CD4+ T cells (27).