One hundred serum samples from 52 COVID-19 patients and 48 convalescents, confirmed by RT-qPCR (n = 90) and/or by serology (n = 89), had an MFI ≥ 900 (range: 998–6477; median: 3590) for anti-S1 IgG. Here, PSMD1 is linked to COVID-19.