REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
anti-human IgG mAbs MT91/145 purified (working concentration: 15 μg/mL)	Mabtech AB	Cat#3850-3-1000
anti-human IgG mAbs MT78/145 biotinylated (working concentration: 1 μg/mL)	Mabtech AB	Cat#3850-6-1000
Human anti-WASP mAb 36-5-10-ALP (working dilution: 1 in 275)	Mabtech AB	Cat#3745-9A-1000
Chemicals, peptides, and recombinant proteins
RPMI 1640 media	Gibco	Cat#22400121
Fetal bovine serum (FBS)	R&D Systems	Cat#S12550H
Penicillin/Streptomycin	Gibco	Cat#15140122
Phosphate-buffered saline (PBS)	Gibco	Cat#10010023
Ethanol	Sigma-Aldrich	CAS 64-17-5
BCIP/NBT-plus substrate	Mabtech AB	Cat#3650-10
StimPack Memory B cells (R848+IL-2)	Mabtech AB	Cat#3660-1
SARS-CoV-2 RBD-WASP (working dilution: 1 in 25)	Mabtech AB	Cat# 3654-TP-10
Streptavidin-ALP (working dilution: 1 in 1000)	Mabtech AB	Cat#3310-10-1000
Rely+On™ Virkon™ Powder	Lanxess (VWR)	Cat#148-0201
Critical commercial assays
ELISpot PVDF plates clear	Mabtech AB	Cat#3654-TP-10
BD Vacutainer® CPT™ Mononuclear Cell Preparation Tube - Sodium Citrate	BD Biosciences	Cat#362760
Deposited data
Decreased memory B cell frequencies in COVID-19 delta variant vaccine breakthrough infection	EMBO Molecular Medicine	https://doi.org/10.15252/emmm.202115227