1. how does the immune system protect us from disease?
2. how do doctors use the immune response to protect you from disease?
3. what are some ways that diseases spread?

Answer No 1:

As soon as a foreign substance enters our body, the immune system detects the foreign substance as an antigen and starts producing antibodies against it. The antibodies kill the antigens and also memory cells of the immune system generate a memory against the antigen. If the antigen invades the body again, then the memory cells immediately detect it and start fighting it.

Answer No 2:

Doctors apply the phenomenon of body's natural immune defense mechanism to produce vaccines. Vaccines are produced so that a person makes antibodies for a particular antigen and when the body gets invaded by that antigen in future, it is readily detected and an immune response is generated. Vaccination contains the antigen in a killed or weakened state so that it is not harmful to the body.

Answer No 3:

Infectious diseases can spread by different ways: