甲型流感病毒(简称流感),自1933年发现以来,已有40多年的厂史。但对于该型病毒引起的流感流行,至今尚缺乏有效的预防措施。由于病毒的表面抗原的易变特性,是引起流感流行的主要因素,因此经常从流感患者中分离病毒,观察和研究流感病毒抗原的变异动态,进一步认识变异的规律性, Influenza A (referred to as flu), since its discovery in 1933, has 40 years of history. However, no effective preventive measures have been taken so far for the influenza-induced pandemic. Due to the variable nature of the surface antigen of the virus, which is the main factor that causes the influenza epidemic, the virus is often isolated from the influenza patients, the variation of the influenza virus antigen is observed and studied, and the regularity of the mutation is further recognized,