The capsid shell is what protects them, and as scientists discovered their structure, they proposed that capsids could have different sizes and hold different amounts of genome, and therefore could infect hosts differently.
衣壳是病毒的保护层，当科学家发现衣壳的结构时，他们提出衣壳有不同的大小并且携带不同数量的基因组，因此病毒能够以不同的方式感染宿主。