Fig. 2.

Determination of the key amino acid sites mediating broad-spectrum antigenicity in Pep1 and Pep6. The red dotted line represents the critical value. There were five serum samples for each genotype. Each experiment was repeated twice. The results show the mean values. (A) Broad-spectrum antigenicity of the synthetic peptides. (B) Strategy for the identification of key amino acids. The black dots represent the same amino acid. The red box represent peptides that could react with positive serum against CK/CH/2010/JT1 strain. (C) Broad-spectrum antigenicity of Pep1-1-2. (D) Broad-spectrum antigenicity of Pep1-1-4. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)