IBV-specific systemic IgG and mucosal IgA responses. Chickens (N = 15) were vaccinated with sterile PBS, JOL2068 or JOL2077, and 28 days later serum and intestinal wash samples were analysed for S1-specific IgG and IgA responses, respectively, by an indirect ELISA. A Serum IgG. B Intestinal sIgA responses. Each data point represents mean ± SD of six chickens. *p < 0.05.