Correlation among SARS-CoV-2-, avian coronavirus infectious bronchitis virus-, SARS-CoV-2 peptide-, rhinovirus-, human herpesvirus 4-specific IgG in poultry farm personnel, COVID-19 patients, and pre-COVID-19 controls
A positive correlation between IBV-specific IgG and SARS-CoV-2-specific IgG may be indicative of the presence of cross-reactive antibodies. The strongest positive correlations between SARS-CoV-2- and IBV-specific IgG were observed in poultry farm personnel (Figure 5A, marked by green square), while there were no significant positive correlations between SARS-CoV-2 antigen-specific IgG and IBV-specific IgG in COVID-19 patients. Only one negative correlation (r=-0.3456; p<0.05) was found between N-specific IgG and 4/91-specific IgG in COVID-19 patients (Figure 5B, marked by green square). We observed moderate positive correlations in the pre-pandemic control group between IS/1494/06- and S1- specific IgG, 4/91- and RBD-specific IgG, IS/1494/06- and RBD-specific IgG, M41- and RBD-specific IgG, D274- and RBD-specific IgG, IS/1494/06- and S2-specific IgG, 4/91- and N-specific IgG, IS/1494/06- and N- specific IgG, and M41- and N-specific IgG (Figure 5C, marked by green square). The individual graphs of Spearman correlation analysis for each SARS-CoV-2 and IBV antigens are shown in Figure S5A-C. Only the significant correlations are shown.
There were no significant correlations between SARS-CoV-2 peptide-specific IgG and IBV-specific IgG in poultry farm personnel (Figure 5A, marked by yellow rectangle). We observed negative correlations between several SARS-CoV-2 peptide-specific IgG and IBV-specific IgG in COVID-19 patients and pre-pandemic control group (Figure 5B,C, marked by yellow rectangle). The only significant positive correlation in poultry farm personnel between SARS-CoV-2 antigen- and SARS-CoV-2 peptide-specific IgG was between N- and N (153-176)-specific IgG (Figure 5A, marked by red rectangle). In contrast, COVID-19 patients showed significant positive correlations between all SARS-CoV-2 antigen- and SARS-CoV-2 peptide-specific IgG except for ORF3a (172-205)- and S (807-830)-specific IgG and N (153-176)- and S2-specific IgG not (Figure 5B, marked by red rectangle).
Spearman correlation results of IgG OD ratios of vaccine implementers and poultry workers were presented in Table S8 and were compared via their r values. There were remarkable differences in the level of correlations between SARS-CoV-2 antigen- and IBV-specific IgG OD ratios in 4/91 (S2 and N), IS/1494/06 (S1), D274 (S2). In this context, vaccine implementers had higher r values compared to poultry workers in Spearman correlation analysis (Figure S6A,B; Table S8).
The S1-, RBD-, and N-specific IgG negatively correlated with both rhinovirus- and human herpesvirus 4-specific IgG in COVID-19 patients. There were no significant correlations between SARS-CoV-2- and rhinovirus-, SARS-CoV-2-, and human herpesvirus 4-specific IgG in poultry farm personnel and pre-pandemic control group (Figure 5A-C).