CD4 and leishmaniasis: Administration of killed P. acnes as an adjuvant increased the resistance to infection by T. cruzi (Mussalem et al., 2006) and in leishmaniasis this adjuvant was used in murine vaccination with native and recombinant antigens resulting in protective immunity mediated by CD4+ Th1 lymphocytes (Pinto et al., 2000; Ferreira et al., 2008).