herd immunity

例句：

1. 1. The herd immunity provided by the vaccine is crucial for controlling the spread of the disease.
   疫苗提供的群体免疫对于控制疾病的传播至关重要。
2. 2. In herd immunity, animals that are infected with the virus do not transmit it to others.
   在群体免疫中，感染了病毒的动物不会将病毒传给其他人。
3. 3. The herd immunity measures have been effective in reducing the number of cases in the community.
   这些群体免疫措施已经有效地减少了社区中的病例数量。