From 13 months to 28 months after discharge, the proportion of HCWs with severe COVID-19 with decreased relative numbers of CD3+ T cells decreased from 11.9 to 6.6%, the proportion of HCWs with severe COVID-19 with increased relative numbers of NK cells decreased from 8.6 to 5.5%, showing a trend of improvement, but the proportion of those with decreased relative numbers of CD8+ T cells increased slightly (3.9 vs. 6.6%). Here, CD8A is linked to COVID-19.