SARS-CoV-2 specific serum IgG (AU/ml), as measured by iFlash 1800 chemiluminescent immunoassay (YHLO, China), in 15 patients with severe COVID-19 and 32 patients with mild COVID-19 over >90 days follow-up post symptom onset. SARS-CoV-2 receptor binding domain specific serum IgM, IgG and IgA in samples collected >75 days post symtom onset from 21 patients with mild or severe COVID-19. Measured by in-house ELISA, results presented as AUC of titration curve.