Fig. 6.

Non-severe and severe COVID19. a) During non-severe stage, innate and specific adaptive immune responses can eliminate the virus and prevent disease progression to severe stages. b) Nevertheless, high viral load and propagation, followed by dysregulated immune response and massive destruction of the affected tissues can induce innate inflammation in the lungs that is largely mediated by inflammatory monocyte-macrophages (IMMs). Massive accumulation of pathogenic inflammatory IMMs and exuberant inflammation increase the severity of disease and lead to lung damage in the severe stages of the disease.