Antivirals (Exam V)

Question 1

Are viruses alive or dead?
What are they?

Answer 1

• Neither (can be active or inactive)
• Obligate intracellular parasites

Question 2

What two components do all viruses have?

Answer 2

• Capsid (external coating)
• Core of nucleic acids

Question 3

What does the statement “most viruses are self-limiting” mean?

Answer 3

• They are dealt with by the body’s innate immune defense mechanisms and require no antiviral medication.

Question 4

What are the two overarching categories of viruses?

Answer 4

• DNA Viruses
• RNA Viruses

Question 5

What sub-category of RNA viruses is unique? How are they different from other viruses?

Answer 5

• Retroviruses
• Reverse Transcriptase mechanism (RNA → DNA vs DNA → RNA → proteins)

Question 6

What type of anti-viral therapy is non-targeted?

Answer 6

Interferon

Question 7

What is a viral capsid?
How would a nucleocapsid differ from this?

Answer 7

• Shell surrounding nucleic acids
• Nucleocapsids are capsid & nucleic acid together.

Question 8

What is a viral envelope usually composed of?

Answer 8

• Modified piece of a host cell membrane

Question 9

Naked viruses consist only of a ____________.

Answer 9

nucleocapsid

Question 10

What component of a virus allows “docking” on host cells?

Answer 10

spikes

Question 11

How does a virion differ from a virus?

Answer 11

• Virion = Fully formed virus able to establish infection in a host cell.
• Virus = No metabolic activity yet (needs to infect something)

Question 12

Virus families are denoted with the suffix _______.

Answer 12

-viridae (herpesviridae)

Question 13

Virus genera are denoted with the suffix ______

Answer 13

-virus (simplexvirus)

Question 14

What is the viral family of the influenza viruses?

Answer 14

• Orthomyoxviridae

Question 15

What is the viral family of HIV?
What about the genus?

Answer 15

• Retroviridae
• Lentivirus

Question 16

What genuses are in the Herpesviridae family?

Answer 16

• Simplexvirus (Herpes Simplex 1 & 2)
• Varicellovirus (Varicella Zoster = chickenpox)

Question 17

What is the viral family of the Hepatitis viruses?
What about the genus?

Answer 17

• Hepadnaviridae
• Hepadnavirus

Question 18

What are the five phases of viral replication?

Answer 18

• Adsorption
• Penetration
• Synthesis
• Maturation
• Release

Question 19

What is the process of viral adsorption?

Answer 19

• Attachment of virus to host cell via spike protein

Question 20

What is the process of viral penetration?
What is it called if the entire virus enters the cell?

Answer 20

• Entry of virions (or genome) into host cell
• Uncoating

Question 21

What is the process of viral synthesis?

Answer 21

• Creation of new nucleic acids, capsid proteins, & other viral components.

Question 22

What is the process of viral maturation?

Answer 22

• Assembly of newly created viral components into complete virions.

Question 23

What is the process of viral release?

Answer 23

• Release of new virions from host cells.

Question 24

What two types of viral release exist? Differentiate the two.

Answer 24

• Lytic → rupture of host cells, fast & self-limiting (think GI virus)
• Lysogenic → Slow release, makes host cell become viral factory. Can become lytic eventually.

Question 25

What is the prototypical, first antiviral drug? What is its mechanism of action?

Answer 25

- Acyclovir - Inhibition of viral DNA synthesis

Question 26

What is the indication for Acyclovir?

Answer 26

HSV & VZV

Question 27

What is acyclovir's mechanism of action?

Answer 27

- Impersonates the deoxyribose sugar of a DNA chain. Missing a hydroxyl group so the chain ends up terminating.

Question 28

When is acyclovir indicated? Does this change for pregnancy?

Answer 28

- HSV 1 & 2, and VZV infections. - Beneficial in pregnant women, ↓ viral shedding and ↓ c-section rate.

Question 29

What viral component allows HIV to bind to CD4⁺ T-lymphocytes?

Answer 29

- gp120 spike protein

Question 30

Which antiviral is a inhibitor of reverse transcriptase? What is the therapy called when this drug is combined with others to treat HIV?

Answer 30

- Azidothymidine (AZT) Zidovudine - Highly Active Antiretroviral Therapy (HAART)

Question 31

Which drugs have activity against both HBV and HIV?

Answer 31

- Lamivudine - Telbivudine - Tenofivir

Question 32

When would one use Tenofivir?

Answer 32

- HIV & HBV - **Lamivudine-resistant HBV**

Question 33

How do Lamivudine & Telbivudine work?

Answer 33

- Inhibition of HBV DNA polymerase - Inhibition of HIV reverse transcriptase

Question 34

Interferon can be used for ____________ but it's better at treating _______ ________.

Answer 34

viruses ; autoimmune diseases

Question 35

What antivirals are available to treat influenza?

Answer 35

- Oseltamivir (Tamiflu) - Zanamivir (Relenza) - Baloxivir Marboxil (Xofluza)

Question 36

When must tamiflu be give to be successful? How much efficacy do antiviral influenza drugs have?

Answer 36

- 48hrs - Usually shorten course of illness by 1 day.

Question 37

Who should not be given Relenza (Zanamivir) for their influenza infection? Why?

Answer 37

- Patients with asthma & COPD - Relenza is an inhaled medication

Question 38

Which influenza antiviral is a one-time dose pill? Who cannot receive this medication?

Answer 38

- Xofluza (Baloxivir Marboxil) - Pregnant and/or breastfeeding mothers, & hospitalized or very ill patients

Question 39

What human cell surface antigens are used to categorize influenza subtypes?

Answer 39

- Hemaglutinin (H1, H2, H3) - Neuramindase (N1, N2)

Question 40

What role does human hemaglutinin have influenza infection?

Answer 40

- Viral attachment to human cells

Question 41

What role do human neuraminidases have in influenza infection?

Answer 41

- Cell Penetration

Question 42

Between Flu A & Flu B, which is generally more severe?

Answer 42

- Influenza A.

Question 43

Which Influenza subtype has less antigenic shift and is generally more mild? Who is generally more affected? Does this flu infect anything other than humans?

Answer 43

- Influenza B - Children - Seals

Question 44

What is the progression of a COVID infection?

Answer 44

Attachment to ACE receptors → inflammatory mediators → WBCs → Cytokine Storm.

Question 45

What severe outcomes can occur with cytokine storm?

Answer 45

- ARDS - Multi-Organ Failure - Hyperinflammation syndrome - Death

Question 46

What gene may be responsible for an increased susceptibility to COVID infection/severity?

Answer 46

- *Alu* Polymorphism in ACE receptors

Question 47

What PO drug has been approved for COVID infection?

Answer 47

- Paxlovid

Question 48

What parenteral drugs have been approved for COVID? Give their MOAs.

Answer 48

- Remdesevir - chain termination inhibiting new viral synthesis. - MABs - block COVID entry into cells