All patients with pneumonia caused by SARS-CoV-2 who develop SRF display hyper-inflammatory responses with features of either immune dysregulation or MAS, both of which are characterized by pro-inflammatory cytokines: the immune dysregulation described here, which is driven by IL-6 and not by IL-1β, and MAS, which is driven by IL-1β. There are two key features of this immune dysregulation: over-production of pro-inflammatory cytokines by monocytes and dysregulation of lymphocytes characterized by CD4 lymphopenia and subsequently B cell lymphopenia. In parallel, the absolute natural killer (NK) cell count is depleted, probably as result of the rapidly propagating virus.