Question

3. An individual with AIDS has a low TH count. What is the clinical significance/meaning of this low count?

4. (a) List the different protective effects of antibodies. (b) Why are memory cells important?

5. (a) Distinguish between active and passive immunization. (b) Provide examples of each type of immunization.

Answer 1

3. An individual with AIDS has a low CD4* count. What is the clinical significance/meaning of this low count?
Ans) A low CD4 count means that HIV has damaged your immune system and may be making you ill. HIV treatment will strengthen your immune system and extend your life. While your CD4 count is low, you may also need to take antibiotics to prevent infections.

Ans4)

a) neutralization of infectivity

Phagocytosis
Antibody-dependent cellular cytotoxicity
   Complement-mediated lysis of pathogens or of infected cell

b) because Memory cells record information for your immune system about how to fight and destroy viruses and the like that plague the body. When a disease strikes the body the memory cells instruct the body on how to produce antibodies. Once created, these antibodies are released into the bloodstream.

Ans5)

a)

Active immunization	passive immunization
Own immune system is stimulated to produce antibodies and lymphocytes immune system actively involve arise naturally when an individual is exposed to an antigen or pathogen involve both humoral and cell mediated immunity component are T cells, B cells and antigen presenting cell active immunity results in the formation of long-lasting memory cell	Receive Antibodies or lymphocytes that have been produced by another individual immune system not actively involve but rather passive arise naturally when foetus receive through placenta or breast feeding only by readymade antibodies no immune cell involve as antibodies memory immune cells are not formed

b) example of active immunization

• Natural - producing antibodies in response to exposure to a pathogenic infection such as measles or cold
• Artificial- producing antibodies to controlled exposure to an attenuated pathogen

examples of passive immunization

• Natural - receiving antibodies from mother to foetus or during breast feeding
• Articial - receiving manufactured antibodies via external delivery for eg. blood transfusion of monoclonal antibodies