Figure 4.

 Differentiation of vaccinated chickens from vaccinated and then infected chickens and changes in hemagglutination inhibition (HI) titers following infection. Serum samples were taken 3 weeks post‐vaccination from 2⁸ and 2¹⁰ VLP‐vaccinated chickens. 10 days post‐challenge (dpc) infection, serum samples were taken from 2⁸ and 2¹⁰ VLP‐vaccinated and then infected chickens. (A) NP antibody levels from each serum samples were tested with commercially available NP‐cELISA Kit. Each dot represents the NP‐specific antibody value of each chicken. (B) Hemagglutination inhibition (HI) titers (log2) against homologous antigen at 10 dpc were compared with pre‐challenge sera. Data shown are the meant titers of each group ± standard deviation.