Question

Which of the following is the most important reason that developing treatments and vaccines, as well as staging an effective immune response for HIV infections, has been so difficult compared with other viruses?

A.

Researchers probably have not yet identified the actual cause of AIDS and thus cannot target their drug development accordingly.

B.

The virus evades the immune system and drugs by hiding inside cells of the immune system, such as helper T cells.

C.

The virus has no recognizable antigens and thus cannot be identified easily by the host's immune system.

D.The virus has few, if any, replication-correcting enzymes, and consequently mutates at a high rate.

If you were trying to create an attenuated virus in order to develop a vaccine, which of the following strategies might you use?

	A.	Isolate the virus, expose it to a culture of bovine cells for several generations, and inject the live virus into a person.
	B.	Use mechanical forces to break the virus into smaller pieces; then inject these pieces into a person.
	C.	Isolate the virus, destroy it with UV light, and inject it into a person.
	D.	Isolate the virus and inject it directly into a person.

Answer 1

(1)-There are lots of reasons behind no vaccine against HIV, but the most important reason is virus evade the immune system and drugs by hiding inside the cells and immune system,such as helper T-cells so,option B is correct

-In helper T-cells this HIV attacks specific type of immune cell known as CD4 helper cell and destroy them which makes our body harder to fight against small infections and consequently we suffer from AIDS (Acquired immune deficiency syndrome).

(2)- Attenuated means alteration in virus i.e. making virus less effective or harmless so that it can not cause any disease

-To develop attenuated vaccine the viruses are grown on those cell or environment where they don`t normally grow in for several generations,The viruses begin to evolve & adopt to this new cell and became less able to live in there preferred environment so option A is true.