The capsid is covered by a protein layer called the tegument, and finally enclosed in an envelope, which is a lipid membrane that contains viral glycoproteins and is acquired from the nuclear membrane of host cells.

衣壳上覆盖有一层叫“间层”的蛋白，最外面由一层囊膜包裹；囊膜是一层包含病毒糖蛋白的磷脂膜，来自于宿主细胞的核膜。