Figure 2

Development of systemic and mucosal immune responses after TGEV infection. (A) TGEV-specific antibodies measured by competitive ELISA are shown as optical densities (OD), measured at 450 nm, from 0 to 18 dpi. An OD₄₅₀ value higher than 0.9 was considered negative (upper dashed line), an OD₄₅₀ value lower than 0.77 was considered positive (lower dashed line), and an OD₄₅₀ value between 0.9 and 0.77 was considered questionable. (B) The concentration of sIgA in intestinal wash fluid was measured by a direct ELISA. Results are shown as the mean value ± standard deviation. Asterisk indicates statistically significant difference (P ≤ 0.05) between the groups.