immune defence

例句：

1. 1.The immune system is the body's first line of defense against infections.
   免疫系统是身体对抗感染的第一道防线。
2. 2.Infections can weaken the immune defences of an individual.
   感染可以削弱个体的免疫力。
3. 3.The vaccine provides a temporary immune defence against the virus.
   疫苗提供了对病毒的临时免疫防御。