To test whether the abundance of antigen-specific CD8+ T cells correlated with disease phenotype and progression, we reanalyzed a large ECCITE-seq dataset (transcriptome, surface protein and TCR) from the COVID-19 multi-omics blood atlas (COMBAT)46, which contains 65,889 CD8+ T cells prospectively collected from 10 healthy controls and 61 COVID-19 patients at the time of admission to inpatient hospital care, and who subsequently manifested mild, severe or critical disease46. Here, CD8A is linked to COVID-19.