Vaccines

Question 1

How are the requirements for generating helper T and B cells different from those for generating memory CTLs?

Answer 1

• memory helper T and B cells can be produced even when an invader does not infect and APC
• memory CTLs can only be made if the attacker infects an APC

Question 2

What are the obstacles to producing an effective AIDs vaccine?

Answer 2

• it isn’t certain which types of memory cells are needed
• needs to stimulate memory CTLs to be effective
• using an attenuated vaccine may work, but high mutation rate means people might develop AIDS

Question 3

What is a subunit vaccine?

Answer 3

• one in which synthetic viral proteins are injected

- no possibility of infection

Question 4

What is the potential drawback of non-infectious vaccines?

Answer 4

-they will generate memory helper T and B cells, but because they do not actually infect any cells, no memory CTLs will be created

Question 5

What is an attenuated vaccine?

Answer 5

• uses a weakened form of the microbe
• when a virus is grown in the laboratory in a cell type which is not its natural host, the virus accumulates mutations which weaken it
• viruses are still infectious, but are too weak to cause the disease in healthy individuals

Question 6

Can attenuated vaccines stimulate the production of memory CTLs?

Answer 6

-yes

Question 7

What are the risks of attenuated vaccines?

Answer 7

• vaccinated person may produce enough virus to infect those around him
• virus may mutate and regain its original strength

**very rare

Question 8

What is a carrier vaccine?

Answer 8

• we put a single genetically engineered gene from a pathogenic microbe into a benign virus
• trojan horse
• no chance of infection

Question 9

What cells must assist CTLs to produce memory CTLs?

Answer 9

-Helper T cells

**makes AIDS vaccine difficult b/c need helper T cells alive