免疫细胞

例句：

1. 1. The vaccine is designed to protect against the common cold.
   这种疫苗旨在预防普通感冒。
2. 2.The immune system can recognize and fight off infections.
   免疫系统能够识别并抵抗感染。
3. 3.Researchers are studying how the immune system works in response to cancer cells.
   研究人员正在研究免疫系统如何响应癌细胞。