Thermal stability of neuraminidase in influenza vaccine / 中国生物制品学杂志

@#Abstract：Objective To analyze the stabilities of neuraminidase（NA）in influenza vaccine at different temperatures and provide a reference for further complete understanding of overall shelf life of vaccines. Methods Monovalent bulks of influenza H1N1，H3N2 and B vaccines were stored at 4（low temperature），25（room temperature）and 37 ℃（changed temperature）for 0. 5，2，7，24 and 48 h separately，using that at 100 ℃（extreme temperature）for 1 h as control，and determined for NA activity by enzyme⁃linked lectin method. Results The NA activities of influenza H1N1 vaccines stored at 25 and 37 ℃ decreased significantly with the increasing of time. No significant decreases were observed in H3N2 and B vaccines even after storage at two non⁃storage temperatures for 48 h. However，all the NA activities of three vaccines decreased at 100 ℃. Conclusion Both H3N2 and B vaccines showed high stability at abnormal storage temperatures not more than 37 ℃，while H1N1 vaccine was relatively sensitive to the temperature for storage.

Prediction of antigenic epitopes on HA, NA amino acid sequences of novel influenza A (H7N9) virus and analysis association between susceptibility and HLA-Ⅱalleles / 中国免疫学杂志

Objective:To compare the amino acid sequences difference of HA,NA novel influenza virus A/H7N9 isolates, decipher possible B cell epitopes and T cell epitopes of HA,NA protein,and analyze the association between susceptibility and HLA polymorphisms.Methods:The amino acid sequences of novel influenza A ( H7N9) virus were downloaded from Genbank.Phylogenetic trees were constructed based on the amino acid sequences of HA and NA by using software Clustal X and MEGA 4.0.B cell and T cell epitopes were respectively predicted with Protean software and NetMHCⅡ2.2 Server online server.Results:The homology of HA and NA proteins of H7N9 virus was high.10 B cell epitopes and 15 T cell epitopes were randomly distributed throughout HA sequence and 12 B cell epitopes and 9 T cell epitopes were randomly distributed throughout NA sequence.HLA-DRB1*0701 allele which was commonly observed in Northern Chinese population have a high binding affinity for 9-mer peptides of HA and NA proteins.Conclusion:The prediction of B and T cell epitopes of HA and NA proteins with multiple methods benefits the research and development of vaccine against human infection with avian influenza A H7N9 virus.HLA-DRB1*0701 allele may contribute to susceptibility to novel influenza A (H7N9) virus.H7N9 influenza virus is more easily spread in Urumqi,Harbin,Shandong Province,Liaoning Province,Beijing, Shijiazhuang and Tianjin of China.