Antivirals and Vaccines

Question 1

How do antivirals work?

Answer 1

Block specific steps in virus life cycle

Question 2

What is necessary for antivirals?

Answer 2

Must be active against virus replication, but not notmal celular function

Question 3

Why is continued antiviral development required?

Answer 3

Virus resistence

Question 4

What antivirals prevent entry?

Answer 4

Enfuvritide
Amantadine
Rimantadine

Question 5

Enfuvritide

Answer 5

Prevents HIV from entering cell

Blocks refolding og gp41, which prevents membrane fusion

Question 6

Amantadine and Rimantadine

Answer 6

Prevents Influenva from entering host cell

Blocks influenza ion channel (M2), preventing nucleocapsid release at the end of the cell entry process

Question 7

What antivirals Prevent Genome Replicaiton

Answer 7

Acyclovir
Glaniclovir
Valganciclovir
Forscarnet
Ribavirin

Question 8

Acyclovir

Answer 8

Acts as a nucleoside inhibitor for treatment of herpesvirus infections
First antiviral approved for clinical use
Most effective against HSV-1 and HSV-2, less effective against EBV, even less efective agains CMV

Question 9

Glaniclovir

Answer 9

Effective against CMV - prevents genome replication

More toxic, due to interference with cellular kinase

Question 10

Valganciclovir

Answer 10

Nucleoside inhibitor for EBV

Improved oral bioavailability

Question 11

Forscarnet

Answer 11

Herpesvirus treatment
Prevents viral polymerase activity
IV administration
Toxic

Question 12

Ribavirin

Answer 12

Nucleoside inhibitor for RNA viruses
Many mechanisms
Triphosphate inhibits polymerases
Monophosphate form inhibits inosine monophosphate dehydrogenates, lowering GTP in cell
Impairs capping of mRNA

Question 13

Which antivirals prevent viral proteases

Answer 13

Ritonavir

Question 14

Ritonavir

Answer 14

Treatment of HIV
Blocks cleavage of Gag-Pol polypeptode
Boosts the activity of other protease inhibitors because it also blocks the action of cellular proteases that act on other viral protease inhibitors

Question 15

What are some antiviral challenges

Answer 15

Bioavailability
Specificity
Toxicity

Question 16

Bioavailability of antivirals

Answer 16

Absorption into the body
Transport to site of infection
Intake by the cell
Therapeutic window (half-life)

Question 17

Specificity of antivirals

Answer 17

Target the virus activities exclusively or with great preference

Question 18

Toxicity of antivirals

Answer 18

Low impact on the patient

Question 19

Natural Antivirals

Answer 19

Interferons

• more effective against RNA viruses than DNA viruses
• mechanism ofa ction is not well understood

Question 20

Vaccination

Answer 20

The practice of inducing immunity to a pathogen

Question 21

What are the 2 ways to introduce a pathogen?

Answer 21

Active immunization

Passive immunization

Question 22

Active Immunization

Answer 22

Administering all or part of a pathogenic gent to induce antibodies or cell mediated immunity

Question 23

Passive Immunization

Answer 23

Administration of exogenously produced antibodies

Question 24

What are the 2 forms of vaccines

Answer 24

Live, attenuated

Killed

Question 25

What are the three important immune cell types in vaccinations

Answer 25

B cells
CD8+ T-cells
CD4+ T-cells

Question 26

What vaccines utilize B cells only?

Answer 26

Pneumococcal

HIB (unless conjugated to other antigens)

Question 27

Which vaccines utilize B and T cell immunity

Answer 27

Influenza
Polio
Typhoid

Question 28

What are some considerations to take for vaccines

Answer 28

Age

Special Populations

Question 29

Why is age taken into considerations for vaccines?

Answer 29

Young children and the elderly have weaker immune systems, and they may not be able to respond to live, attenuated vaccines

Question 30

Why are special populations taken into consideration for vaccines?

Answer 30

Immunocompromised persons may have greater need of vaccination or be counter-indicated for vaccine
There can be other complications, such as small pox vaccines for persons with eczema