At the time of euthanasia (acute stage of T. cruzi infection), IL-4, IL-6, and IL-10 levels had a small increase in the four groups that were infected (three immunized and one was not), while in the immunized but not-infected groups, concentrations remained similar to those at the post-immunization/pre-infection time (p > 0.05). This evidence concerns the gene IL6 and infection.