Antivirals Flashcards
What is a virus?
Sub-cellular, inter-cellular parasites.
What is a virion?
Mature virus particle outside of sub-cell.
What are examples of sicknesses caused by viruses?
Ebola, SARS, flu, smallpox
Are there any broad-spectrum antivirals?
No.
What is Influenza type C?
Causes mild or no symptoms.
What is Influenza type B?
Primarily human disease. Milder than type A. No sub-types. Has strains though.
What is influenza type A?
Multiple sub-types (H1NI). Can affect humans and animals. Can cause pandemic.
What kind of genome do Influenza type A and B have?
RNA genome, but segmented.
What major two cell surface proteins do Influenza type A and B have?
- Hemagglutinin. 2. Neuraminidase.
What does the H1 stand for in (for example) H1N1?
The specific type of Hemagglutinin.
What does the N1 stand for in (for example) H1N1?
The specific type of Neuraminidase.
What is influenza re-assortment?
Mixing two genomes of the same type of virus.
How is it thought that H1N1 developed?
Quadruple re-assortment.
What is an antigenic DRIFT?
Small, gradual changes due to point mutations in the HA and NA genes.
What is an antigenic SHIFT?
Sudden, major change to produce a novel virus that was not currently circulating among people (re-assortment-influenza a).
When can antigenic shifts lead to pandemics?
- New virus is introduced into human population. 2. Can cause serious illness in humans. 3. Easy person to person spread.
When is a new strain produced?
As a result of antigenic drift.
When are new sub-types produced?
As a result of antigenic shift.
What does Hemagglutinin do?
It binds to its receptor on the hosts cell allowing virus to bind and enter host.
What does Neuraminidase do?
Enzyme that allows for progeny budding and release of buds.
What do Neuraminidase and Hemagglutinin affect?
Sialic acid. Hemagglutinin binds to it. Neuraminidase gets rid of it.
What kind of drug is Zanamivir (Relenza)?
It is a Neuraminidase inhibitor.
What kind of drug is Oseltamivir (Tamiflu)?
It is a Neuraminidase inhibitor.
How do neuraminidase inhibitors work?
Progeny viruses can not escape host cell.
What is the problem with neuraminidase inhibitors?
They must be taken within 48 hours of infection.
Which neuraminidase inhibitor can be taken orally?
Oseltamivir (Tamiflu).
What kind of drug is Peramivir (Rapivab)?
A neuraminidase inhibitor.
How is Peramivir (Rapivab) taken?
Via IV.
How is Zanamivir (Relenza) taken?
Via powder that needs to be inhaled.
What side effects do neuraminidase inhibitors have? (2)
- Can cause serious allergic reactions. 2. Neuropsychiatric problems.
What kind of drug is T-705 (favipiravir)?
Targets Viral RNA dependent RNA polymerase.
How does Favipiravir work?
It targets Viral RNA dependent RNA polymerase, leading to the polymerase making lethal mistakes in viral RNA.
