We all know that vaccine is actually weak form of virus,basically they are the same,the difference is in the degree of virulence,yet causing opposite results on a normal body.

• 大家知道疫苗就是毒性大大减弱的病毒，两者在质上是相同的，区别在于毒性这个量上，可是它们对于一个正常人的肌体的作用却是截然相反的。