Antibody landscape against SARS-CoV-2 reveals significant differences between non-structural/accessory and structural proteins

Antibodies against non-structural proteins of SARS-COV-2 has not been well-studied. Here, the authors investigated the proteome landscape of antibody response against a panel of total 20 proteins of SARS-CoV-2. They found that antibodies against NSP1, NSP7, NSP8, RdRp, ORF3b and ORF9b were detected from sera of COVID-19 patients, although their levels were remarkably lower than those of N and S proteins. The level of IgG against NSP1, NSP7, NSP8, RdRp, ORF3b and ORF9b in sera of COVID-19 patients was well-correlated with the disease severity. Antibodies against these non-structural proteins were decreased after 20 days after symptom onset regardless of disease severity. In contrast, a remarkable decline of IgG antibodies against S1 and N proteins before death was observed.