REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
6x-His Tag Monoclonal Antibody (HIS.H8)	ThermoFisher Scientific	Cat# MA1-21315; RRID AB_557403
Peroxidase AffiniPure F(ab')₂Fragment Goat Anti-Human IgG, Fcγ fragment specific	Jackson ImmunoResearch	Cat# 109-036-098; RRID: AB_2337596
Peroxidase AffiniPure Goat Anti-Human Serum IgA, α chain specific	Jackson ImmunoResearch	Cat# 109-035-011; RRID: AB_2337580
Peroxidase AffiniPure F(ab')₂ Fragment Goat Anti-Human IgM, Fc5μ fragment specific	Jackson ImmunoResearch	Cat# 109-036-129; RRID: AB_2337598
CD40 Antibody, anti-human, pure-functional grade clone HB14	Miltenyi Biotec	Cat# 130-094-133; RRID:AB_10839704
CD49d (Integrin alpha 4) Monoclonal Antibody Clone 9F10, Functional Grade	ThermoFisher Scientific	Cat# 16-0499-85; RRID: AB_468973
BD Horizon™ R718 Mouse Anti-Human CD5 clone UCHCT2	BD Biosciences	Cat# 567058; RRID:AB_2916409
BD Pharmingen™ APC-H7 Mouse anti-Human CD8 clone SK1	BD Biosciences	Cat# 560179; RRID: AB_1645481
BD Horizon™ BV605 Mouse Anti-Human CD4 clone RPA-T4	BD Biosciences	Cat# 562658; RRID: AB_2744420
BD Horizon™ BV421 Mouse Anti-Human CD25 clone 2A3	BD Biosciences	Cat# 564033; RRID: AB_2738555
BD Horizon™ V500 Mouse Anti-Human CD14 clone M5E2	BD Biosciences	Cat# 561391; RRID: AB_10611856
BD Horizon™ V500 Mouse anti-Human CD19 clone hib19	BD Biosciences	Cat# 561121; RRID: AB_10562391
BD OptiBuild™ BB700 Mouse Anti-Human CD154 (CD40L) clone trap-1	BD Biosciences	Cat# 745814; RRID: AB_2743265
BD Pharmingen™ APC Mouse Anti-Human CD137 clone 4B4-1	BD Biosciences	Cat# 550890; RRID: AB_398477
PE/Cyaine7 anti-human CD134 (OX40) Antibody clone Ber-ACT35 (ACT35)	BioLegend	Cat# 350012; RRID: AB_10901161
PE anti-human CD69 Antibody clone FN50	BioLegend	Cat# 310906; RRID: AB_314841
Bacterial and virus strains
pNL4-3.Luc.R-.E−	NIH ARP	Cat# 3418
SARS-CoV-2.SctΔ19	Paper	Pradenas et al.,34 Med NY 2021
pcDNA3.4-TOPO	GeneArt/Thermo Fisher Scientific	Cat# 810330DE
pVSV-G	Clontech	Sánchez-Palomino et al., Vaccine 2011
Biological samples
Participant sera	This study	N/A
ELISA standard, positive plasma sample	This study	N/A
Chemicals, peptides, and recombinant proteins
SARS-CoV-2 (2019-nCoV) Spike S1+S2 ECD-His Recombinant Protein	Sino Biological Inc	Cat# 40589-V08B1
SARS-CoV-2 (2019-nCoV) Spike RBD-His Recombinant Protein	Sino Biological Inc	Cat# 40592-V08H
SARS-CoV-2 (2019-nCoV) Nucleocapsid-His recombinant Protein	Sino Biological Inc	Cat# 40588-V08B
Guanidine hydrochloride solution BioUltra, ∼8 M in H2O	Merck Life Science SLU	Cat# 50937
MACS BSA solution	Miltenyi Biotec	Cat# 130-091-376
Phosphate Buffered Saline	Thermo Fisher Scientific	Cat# 10010015
o-Phenylenediamine dihydrochloride	Merck Life Science SLU	Cat# P8787-100TAB
H2SO4	Sigma-Aldrich	Cat# 258105-1L-PC-M
Fetal Bovine Serum	Thermo Fisher Scientific	Cat# 10270106
Dulbecco’s Modified Eagle Medium	Thermo Fisher Scientific	Cat# 41966052
Expi293 Expression Medium	Thermo Fisher Scientific	Cat# A1435102
Opti-MEM I Reduced Serum Medium	Thermo Fisher Scientific	Cat# 31985070
ExpiFectamine 293 Transfection Kit	Thermo Fisher Scientific	Cat# A14524
Versene	Thermo Fisher Scientific	Cat# 15040033
Puromycin	Thermo Fisher Scientific	Cat# A1113803
DEAE-Dextran	Sigma-Aldrich	Cat# D9885-100G
BriteLite Plus Luciferase	PerkinElmer	Cat# 6066769
CytoStim™, human	Miltenyi Biotec	Cat# 130-092-173
PepTivator ® SARS-CoV-2 Prot_S1, research grade, RG 60nmol	Miltenyi Biotec	Cat# 130-127-048
Human TruStain FcX™ (Fc Receptor Blocking Solution)	BioLegend	Cat# 422301
Critical commercial assays
ELISpot Flex: Human IFN-γ (ALP)	Mabtech	Cat# 3420-2A
AP Conjugate Substrate Kit	BioRad	Cat# 1706432
LIVE/Dead™ Fixable Aqua - Dead Cell Stain Kit (405 nm)	ThermoFisher Scientific	Cat# L34957
Experimental models: Cell lines
Expi293F GnTI- cells	Thermo Fisher Scientific	Cat# A39240
HEK293T/hACE2 cells	Integral Molecular	Cat# C-HA101
Software and algorithms
FlowJo (Treestar)	BD Biosciences	https://www.flowjo.com
GraphPad Prism v8.0	GraphPad Software	https://www.graphpad.com/scientific-software/prism/