IL4 and COVID-19: Although IL-4 is increased in the COVID-19 group, indicating Th2 response, when assessing IL-13 tissue expression and M2 macrophages score, both were decreased when compared to the H1N1 group (p = 0.007 and p = 0.05, borderline; respectively), suggesting the Th2 proliferative phase was not triggered (Table 2).