immunisin

例句：

1. 1. The vaccine contains an immunostin that stimulates the body's immune system to fight off the virus.
   疫苗中含有一种免疫素，刺激身体免疫系统对抗病毒。
2. 2. The researcher found that the immunostin in the vaccine had a significant impact on the patient's recovery.
   研究者发现疫苗中的免疫素对患者的康复产生了显著影响。
3. 3. The study suggests that the immunostin may be a key factor in preventing the spread of the disease.
   研究表明，免疫素可能是预防疾病传播的关键因素。