Palese P, Young J F
Science. 1982 Mar 19;215(4539):1468-74. doi: 10.1126/science.7038875.
Influenza is caused by highly variable RNA viruses belonging to the orthomyxovirus group. These viruses are capable of constantly changing the genes coding for their surface proteins as well as for their nonsurface proteins. The mechanisms responsible for these changes in type A influenza viruses include recombination (reassortment) of genes among strains, deletions and insertions in genes, and, frequently, point mutations. In addition, old strains may reappear in the population. Influenza viruses of types B and C appear to vary to a lesser degree. The mechanisms responsible for changes in these viruses are not well characterized.
流感由正粘病毒科中高度可变的RNA病毒引起。这些病毒能够不断改变编码其表面蛋白以及非表面蛋白的基因。甲型流感病毒发生这些变化的机制包括毒株间基因的重组（重配）、基因的缺失和插入，以及频繁出现的点突变。此外，旧毒株可能会在人群中再次出现。乙型和丙型流感病毒的变异程度似乎较小。导致这些病毒发生变化的机制尚未得到充分表征。
