…………. Technology is useful in Vaccines production

The toxic substances produced by the foreign bodies are known as

What plays an important role in primary and secondary response?

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 ?

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