Figure 5.

Antibody responses to the four immunodominant regions in patients with varying severity of COVID-19 due to the WT virus. Antibody responses to the four immunodominant regions were measured by an in-house ELISA, in patients infected with the WT of SARS-CoV-2 with mild (n = 16) and severe disease (n = 9) during early illness (<7 days since onset of symptoms) (A) and late illness (21–28 days since onset of symptoms) (B). The antibody responses to the four regions were correlated with ACE2-blocking antibodies measured by the surrogate virus neutralization test, and the ACE2-blocking antibodies did not correlate with the levels of the four immunodominant regions (C). The Mann–Whitney U test (two-tailed) was used to determine the differences in antibody levels between those with mild and severe disease. All tests were two-sided. The error bars indicate the median and the interquartile ranges.