Prevention and treatment of viral disease Flashcards
(19 cards)
What are the differences between therapeutic and prophylactic treatment?
Therapeutic is upon infection, prophylactic is before the agent is acquired
HOw do vaccinations help?
They are a form of prophylactic treatment, offering immunological memory, to provide lifelong immunity.
What are the types of vaccine?
Live attenuated
- Weakened, activate antigenic response
Inactivated
- Genetic material removed, capsid and proteins still recognisable for respons
Subunit vaccine
- Fractionated - small pieces still recognisable
- Recombinant - bacteria used to integrate viral genomes to form live virus cevor, or DNA vaccine
Which viruses can be acted on by live attenuated vaccines?
Influenza
MMR
Polio
Smallpox
Which viruses can be acted on by inactivated virus vaccines?
Hep A
Japaense encephalitis
Robies
Which viruses can be acted on bysubunit vaccines?
Influenza
Hep B
HPV
How are viruses attenuated to make a live virus vaccine?
Pathogenic virus isolated
Made to grow in monkeys where it accumulates mutations
Mutations deny ability to live in human cell - cannot cause harm
Compare live and inactivated vaccines
Live \+ rapid, borad and long lived \+ cellular immunity - requires attenutation - may revert
Inactivated \+ safe \+ made from wild - requires booster - high doses
What are two viruses that can be treated by both live and inactive vaccines?
Influenza
Polio
- sabin - live
- salk - inactive
Describe the eradication of smallpox
Occurred due to:
- no animal reservoir
- no latent infection
- vaccine was cheap, easy to administer, safe, potent and stable
Why is it difficult to make drugs that act against viral infections>?
Reside inside cells, hard to leave cell intact
As only viral replication stage can be affected, hard for the vaccine to leave cell machinery used intact
Resistance
SPecific diagnosis is needed for nucleoside analogues
What are the types of antiviral drugs?
Nucleoside analogues
Enzyme targeters
Ion channel blockers
Neuraminidase inhibitors
HIV specific
How do nucleoside analogues prevent infection and give an example
Act as chain terminators, inhibiting viral replication by early cxessation
ACYCLOVIR
- Guanosine analogue
- Lack of OH prevents PDE bond forming
- Higher afiinity for viral DNA polmerase than host cell
How do antivirals target influenza?
Ion channel blocker
- M2 channel by adamantanes
How might new antivirals be found?
Rational drug deisgn
- looking for enzyme that is used
- target needs to be modelled
- molecule needs to be made that binds to it to cease function
What are the types of HIV antiretrovirals?
Entry inhibitors
Nucleoside reverse transciptase inhibitors
Integrase inhibitors
Protesase inhibitors
How do NRTIs work
Early termination due to incorporation f drug into DNA strand
How do integrase inhibitors work
Inhibit addition of viral DNA into human genome
How do protease inhibitors work
Inhibit formation of viral mature paritcles
