IL6 and leprosy: The IL-2 concentration declined 2 weeks after vaccination compared to pre-vaccination in control group, but increased in leprosy cured group (−0.02 pg/ml vs 0.92 pg/ml, P = .0147); the IL-6 concentration declined more in leprosy cured group when influenza virus was challenged (−11.52 pg/ml vs −144.38 pg/ml, P < .0001) (Table 5; Fig. 2).