viral strain

例句：

1. 1. The new vaccine is effective against the viral strain that causes the disease.
   这种新疫苗对引起疾病的病毒株有效。
2. 2.Scientists are working on developing a new strain of virus to fight the pandemic.
   科学家们正在研究开发一种新的病毒株来对抗大流行病。
3. 3.The research team isolated a new strain of bacteria that can cause antibiotic resistance.
   研究小组分离了一种能导致抗药性的新细菌株。