REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
Anti-CD45 (clone H130)	BioLegend	Cat# 304028; RRID:AB_893338
Anti-CD3 (clone OKT3)	BioLegend	Cat# 317334; RRID:AB_2561452
Anti-CD8 (clone SK1)	BD Biosciences	Cat# 557834; RRID:AB_396892
Anti-CD56 (clone HCD56)	BioLegend	Cat# 318304; RRID:AB_604100
Anti-CD38 (clone HIT2)	BioLegend	Cat# 303508
Chemicals, Peptides, and Recombinant Proteins
Fixable viability dye eFluor660	eBioscience	Cat# 65-0864
FcR blocking reagent	Meltenyi Biotec,	Cat# 130-059-901
Ficoll-Hypaque gradient	GE Healthcare Life	Cat# 17144002
Goat anti-human IgM/HRP	Biosynthesis	Cat# bs-0345G-HRP; RRID:AB_10892735
Goat anti-human IgG(biotin)	Sino Biological	Cat# SSA009
HRP Mcab mouse anti-human IgG1	BaiaoTong	Cat# C030248
HRP Mcab mouse anti-human IgG2	BaiaoTong	Cat# C030245
HRP Mcab mouse anti-human IgG3	BaiaoTong	Cat# C030246
TMB substrate	Invitrogen	Cat# 00-4201-56
Mouse anti-His monoclonal antibody	Proteintech	Cat# HRP-66005
Recombinant His-tagged NP of SARS-CoV-2	In-house	N/A
Recombinant His-tagged S-RBD of SARS-CoV-2	Lan et al., 2020	N/A
Recombinant main protease of SARS-CoV-2	Lan et al., 2020	N/A
Critical Commercial Assays
Fixation/Permeabilization Solution Kit	BD Biosciences	Cat# 554714
Human IFN-γELISpotpro kit	MABTECH	Cat# 3420-2AST-2
Biological Samples
Human AB serum	GemCell	Cat# 100-512
Sera from HD#1-3	In-house	N/A
Blood samples from HD#4-6	ChuiYangLiu Hospital	N/A
Blood samples from COVID-19 patients	ChuiYangLiu Hospital	N/A
Experimental Models: Organisms/Strains
HuH-7 Cells	Nie et al., 2020	N/A
Software and Algorithms
FlowJo software v10.7	FlowJo LLC	https://www.flowjo.com/; RRID:SCR_008520