In agreement with the above mentioned responses, Seder et al. (51), when describing immune correlates for vaccine-elicited protection against CL, stated that a CD4+ T-Helper 1-type response is considered necessary and even sufficient for infection by L. major, while CD8+ T cells are considered to have an important role in protection following natural infection and may be important for optimizing vaccine efficacy. This evidence concerns the gene CD4 and infection.