Comparison on Immune Efficacy of Avian Influenza Virus Re-5 Strain and SS Strain in Guangxi Sanhuang Chickens

[ Objective] To compare immune efficacy of avian influenza virus （AIV） Re-5 strain （HSN1 subtype） and SS strain （ H9 subtype） in Guangxi Sanhuang chickens. [Method] A total of 180 Sanhuang chickens were selected from a breeding chicken farm in Guilin City of Guangxi and assigned into four groups （ n = 45）. At 145 days old, the chickens in the group I and II were respectively inoculated with AIV Re-5 strain and AIV SS strain, but they were kept in cages separately. The two control groups were not inoculated. Antibody levels were determined at 170 days old. [ Result] The level of antibodies against AIV Re-5 strain was significantly higher in the chickens of the group I and group II than in the corresponding control groups, respectively （ P 〈 0.01 ）. The level of antibodies against AIV SS strain was not significantly different between the group I and its control group or between the group II and its control group. [ Conclusion] The antibody level of chickens can be increased by the AIV Re-5 strain but not by the AIV SS strain.

Conservation of T cell epitopes between seasonal influenza viruses and the novel influenza A H7N9 virus

A novel avian influenza A(H7N9) virus recently emerged in the Yangtze River delta and caused diseases, often severe, in over 130 people. This H7N9 virus appeared to infect humans with greater ease than previous avian influenza virus subtypes such as H5N1 and H9N2. While there are other potential explanations for this large number of human infections with an avian influenza virus, we investigated whether a lack of conserved T-cell epitopes between endemic H1N1 and H3N2 influenza viruses and the novel H7N9 virus contributes to this observation. Here we demonstrate that a number of T cell epitopes are conserved between endemic H1N1 and H3N2 viruses and H7N9 virus. Most of these conserved epitopes are from viral internal proteins. The extent of conservation between endemic human seasonal influenza and avian influenza H7N9 was comparable to that with the highly pathogenic avian influenza H5N1. Thus, the ease of inter-species transmission of H7N9 viruses(compared with avian H5N1 viruses) cannot be attributed to the lack of conservation of such T cell epitopes. On the contrary, our findings predict significant T-cell based cross-reactions in the human population to the novel H7N9 virus. Our findings also have implications for H7N9 virus vaccine design.