Question

Please help me in this question explain it cleary ​

Answer 1

Answer:

This happens because once a virus enters our body, our body starts producing immunity against that particular virus. this gives the body, immunity to further defend the body from virus. Vaccines also work on the same principle.

Hope this helps you !!!

Answer 2

Explanation:

It is because if anyone suffer from such disease he gets vaccinated and the bacteria which is affected by against the infectious bacteria provides immunity to the cell and helps it to fight against the disease and makes the cell ready that the bacteria could not enter once again.