Remarkably, mice previously immunized with IL-6 Tg-PbANKA/LISP2 parasites displayed low parasitemia at day 6 post-challenge, irrespective of the dose of parasites used for immunization (Groups 1 and 2), with a delay in the pre-patent period of 2 days (day 36 versus day 34, highlighted by the log scale representation of the data) as compared to control mice infected with WT PbANKA SPZ (Group 5). Here, IL6 is linked to parasitic infectious disease.