<span>There are three phases of clnic study and one post approval phase required by the Food and Drug Administration (FDA) for a New Drug Application (NDA). Phase IV which is a common stipulation by the FDA includes continual evaluation of the drug after approval has been granted.</span><span />
Answer:
This happens because of our immune system. Our immune system keep record of every attacking microbe. It contains two type of while blood cells firstly is T cell that respond quickly to the attacking microbe. While secondly B cells that recognize those specific cells and fights them off. In addition to that B cells clones itself as memory cells for that disease and will remains in your body for years
Explanation:
di ko po Alam sagot jan ei sorry po