Fig. 1: COVID-19 patient sera can neutralise pseudotyped lentiviruses expressing SARS-CoV-2 spike protein.

a Sera of COVID-19 patients (n = 25) at 1:1000 dilution were incubated with luciferase expressing lentiviruses pseudotyped with SARS-CoV-2 spike (S) glycoprotein protein for 1 hour prior to infection of CHO-ACE2 cells for 48 hours. Infection levels were determined by luciferase assay, and percentage of neutralisation is presented. Recalled SARS patients (n = 13) and healthy controls (HC) were also conducted in parallel. Dotted lines correspond to 50% neutralisation and baseline of HC. b Sera of recalled SARS patients (n = 13, 1:100 dilution) or a healthy control (Healthy) were mixed with pseudotyped lentivirus expressing SARS-CoV or SARS-CoV-2 S glycoprotein, prior to incubation with CHO-ACE2 cells for 48 hours. Infection levels were determined by luciferase assay, and percentage neutralisation was analysed. c Dose–response neutralisation of pseudotyped lentivirus titration curves of COVID-19 patients (n = 41, 1:50 to 1:12,800 dilutions). d Dose–response neutralisation of live SARS-CoV-2 virus titration curves of COVID-19 patients (n = 8, 1:16 to 1:65,536 dilutions). Comparison table of IC₅₀ values from two assays. Lines represent non-linear regression robust fit. Source data are provided as a Source Data File.