IL6 and acute respiratory distress syndrome: The latest retrospective study reviewed 150 confirmed COVID-19 cases, found that sharp increases in ferritin and IL-6 in non-survivors, suggesting that the deaths may have been caused by virally driven hyperinflammation.[46] The rapid production of IL-6 mediate lymphocyte infiltration and activation in the pneumonic lung, which might leads to acute respiratory distress syndrome.[47,48] It is interesting that under the influence of host's immune response elicited by vaccination, the degree of decrease of IL-6 was 14-fold in leprosy cured group than in control group.