Avian coronavirus infectious bronchitis virus-specific IgG levels in poultry farm personnel, COVID-19 patients, and pre-COVID-19 controls
We next analyzed the levels of IgG antibodies specific for the IBV genotypes 4/91, IS/1494/06, M41, and D274. As shown in Figure 2B-D, significant differences were observed for IBV-specific IgG in poultry farm personnel, COVID-19 patients, and pre-COVID-19 controls. In this context, IS/1494/06-specific IgG levels were significantly higher in pre-pandemic control samples compared to COVID-19 patients (P <0.05) (Figure 2B). In addition, the levels of M41-specific IgG in the pre-pandemic control group were significantly higher than in COVID-19 patients (P <0.05) (Figure 2C). The D274-specific IgG OD ratios in poultry farm personnel were significantly higher than in COVID-19 patients (P <0.001) (Figure 2D; Table S7). However, we did not observe significant differences in the 4/91-specific IgG levels, between poultry farm personnel, COVID-19 patients, and pre-pandemic control samples (Figure 2A). In the non-hospitalized and hospitalized COVID-19 patients’ comparison, results revealed that 4/91-, M41-, and D274-specific IgG OD ratios were significantly higher in non-hospitalized cases (P <0.01) (Figure S2A,C,D). However, IS/1494/06-specific IgG OD ratios did not differ significantly in non-hospitalized and hospitalized COVID-19 patients (Figure S2B). There were no significant differences between vaccine implementers and poultry workers in the evaluation of IBV-specific IgG levels (Figure S2E-H). But, here it should be noted that percentage of individuals showing >0.1 IBV-specific IgG values was remarkably higher than poultry workers (Figure 2F).
Among 39 vaccine implementers, 36 (92.31%), 28 (71.79%), 34 (87.18%), and 39 (100%) individuals had >0 IgG ratios for 4/91, IS/1494/06, M41, and D274, respectively. The frequency of individuals with the >0 IgG ratios were 12 (85.71%), 9 (64.29%), 8 (57.14), and 14 (100%) for 4/91, IS/1494/06, M41, and D274, respectively, in a total of 14 poultry workers (Figure 2E).