BCR and COVID-19: To map the immune microenvironment of COVID-19 patients, weidentified mirroring changes in the blood and pinpointed cell-specificalterations associated with disease severity and recovery; we then integratedscRNA-seq, single-cell paired BCR, and single-cell paired TCR analysis from atotal of 10 COVID-19 patients in the early recovery stage (ERS) or late recoverystage (LRS) (70,858 PBMCs).