未分类题

流感病毒的变异有和特点?

【参考答案】

流感病毒中甲型流感病毒最易发生变异。其变异主要是血凝素和神经氨酸酶的变异，前者的变异较后者快。抗原变异幅度小，属于量变，称为抗原性漂移。原因是血凝素或神经氨酸酶基因发生点突变，可引起中小型流行。若抗原变异幅度大，形成新的亚型，属质变，称为抗原性转换，由于人群对新的亚型普遍缺乏免疫力，因此易引起大流行...

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