Figure  3From: Pathogenic characteristics of a QX-like infectious bronchitis virus strain SD in chickens exposed at different ages and protective efficacy of combining live homologous and heterologous vaccinationMean scores in the ciliary activity test at 5, 7, 9 and 14 days post-inoculation (dpi) after infection with IBV strain SD. A Group 1, chickens were infected with 106.0 EID50 of IBV strain SD at 2-weeks old. B Group 2, chickens were infected with 106.0 EID50 of IBV strain SD at 3-weeks old. C Group 3, chickens were infected with 106.0 EID50 of IBV strain SD at 8-weeks old. D Group 4, chickens were infected with 106.0 EID50 of IBV strain SD at 18-weeks old. E Group 5, chickens were infected with 106.0 EID50 of IBV strain SD at 22-weeks old. NC in each panel, not challenged. Statistical significance was considered as follows: significant at p < 0.05 (*), highly significant at p < 0.01 (**) and very highly significant at p < 0.001 (***).Back to article page