Consider the following statements

$I.$ People should get vaccination to avoid infection

$II.$ Vaccination is available against polio, cholera, typhoid, tuberculosis and many othe disease

$III.$ Eradication of vectors are necessary in diseases like malaria and filariasis

$IV. $ Dengue and chikengunya, both are spread by Culex mosquitoes

Which of the statements given above are correct?

$A$ – The vaccines generate memory – $B$ and $T$ – cells. $R$ – In vaccination activated pathogens are introduced into the body.

Which of the following is an autoimmune disorder?

What is Active immunity and Passive immunity ?

Many microbial pathogens enter the gut of humans along with food. What are the preventive barriers to protect the body from such pathogens ? What type of  immunity do you observe in this case ?