Antivirals & Vaccines Flashcards
antivirals block specific _____ in the virus life cycle
steps
antivirals must be active against virus __________, but not normal cellular function to reduce ________
replications, toxicity
antivirals exploit ___________, _________ and _________ info to identify targets
structural, functional, genomic
virus resistance to antiviral drugs is common and requires continued __________ efforts
development
how does enfuvirtide work against HIV?
blocks refolding of gp41, inhibits membrane fusion by preventing conformational change
how do amantadine and rimantadine work against influenza?
blocks influenza ion channel (M2) preventing nucleocapsid release at the end of the cell entry process
how does acylovir treat herpesvirus infections?
- most effective against HSV-1/2 and less for EBV and CMV
- nucleoside analog: eliminates 5-C ring that allows DNA chain growth so further replication falls apart
what is ganciclovir effective against?
CMV but more toxic than acyclovir due to interference with cellular kinases
what is valganciclovir effective against?
activity similar to acyclovir, improved oral bioavailability
what is foscarnet effective against?
herpesvirus treatment: prevents viral pol activity, IV administration, toxic
what do the nucleoside inhibitors of HIV & HBV have in common?
- elimination of -OH group so early DNA chain can’t elongate
- toxicity is an issue
what kind of drug is ribavirin?
- nucleoside inhibitor of RNA viruses
- triphosphate form inhibits pols
- monophosphate form inhibits inosine monophosphate dehydrogenase lowering GTP in cell
- impairs capping of mRNA
what does the maturation of progeny viruses often require?
cleavage of virus polypeptide
what are some antiviral challenges?
- bioavailability: absorption to body, transport to site of infection, intake by cell, therapeutic window
- specificity: targets the virus activities exclusively or with great preference
- toxicity: low impact on patient
where can antivirals affect the viral replication?
- attachment and entry
- penetration
- uncoating
- early protein synthesis
- nucleic acid synthesis
- late protein synthesis and processing
- packaging and assembly
- viral release
interferons are natural antivirals… what type of viruses are they effective against?
more effective against RNA viruses than DNA
what is active immunization?
administering all or part of pathogenic agent to induce antibodies or cell-mediated immunity
what is passive immunization?
administration of exogenously produced antibodies
what are the 2 forms of vaccines?
live, attenuated and killed
reversion is possible with what type of vaccination?
live attenuated vaccines
what are the 3 important immune cell types in vaccination?
B cells, CD8+ T cells, CD4 T cells
what are vaccines called the only utilize C cells??
pneuomoncoccal HIB (unless conjugated to other antigens)
what vaccines utilize B cell and T cell immunity including secretory IgA?
influenza, polio, oral typhoid
what are the typical age groups for vaccines?
young children and the elderly and special populations (immunocompromised individuals)
