Extended Data Fig. 3: Comparative ELISA analysis of SARS sera sampled collected in 2003 and 2020 against RBD of SARS-CoV-2 and SARS-CoV.

Testing was conducted using SARS patient serum collected (a) <1 year of infection (n = 7), and (b) >17 years post infection (n = 10). Indirect ELISA was carried out as described in Methods with patient sera used at the final dilution of 1:50. Paired two-tailed Student’s t-test was used for statistical significance analysis.