Table 2. Overview of proportionally increased cell clusters and transcriptional characteristics in the direct comparison between COVID-19, CAP-flu, and CAP-other.

	COVID-19	CAP-flu	CAP-other
NK cells	Granulysin+ NK cells ↑ higher type I interferon response than CAP-flu NK cells high IFITM3 expression	Granulysin+ NK cells ↑↑ higher AREG expression than COVID-19	Low numbers of NK cells
T cells	CD8 EMRA-like 2 ↑ cytotoxicity, activation and inflammation	CD8 EMRA-like 2 ↑↑ cytotoxicity, activation and inflammation	Naive CD4/CD8 not activated CD8 EM less activated than EMRA-like 1 and 2 clusters
Monocytes	Intermediate monocytes high type I interferon response, increased antiviral potential	Classical monocytes ribosomal and viral transcription genes	Non-classical monocytes heterogenous gene expression