L28: Virology Flashcards
____: Infectious, obligate, intracellular parasites
Viruses
___ ___ derived from host cell harboring viral spike protein, which makes coronaviruses susceptible to hand sanitizers
__ is a viral attachment protein involves in receptor binding and fusion – major vaccine candidate
Lipid Envelope
Spike
Why is the spike a good vaccine candidate?
- Specific to virus that infects us
- Outside of virus - easily recognized
Coronavirus binds to ___ on host cells
ACE-2
True or False: Genetic changes associated with antigenic drift happen continually over time
True
ANTIGENIC SHIFT
____: occurs when two closely related viruses infect the same cell. The resulting shift causes abrupt change.
Example: Flu virus from animal population gains ability to interact with humans
______: can occur in ss nucleic acid viruses; when AT LEAST two viral genomes co-infect same host cell and exchange genetic segments
Ressortment
Recombination
True or False: While viruses change all the time due to antigenic drift, antigenic shift happens less frequently
True
True or False: Coronavirus has segmented genome
False - has a 1 single long stranded genome
True or False: Coronavirus can use mechanism of recombination
true
All major Sars-CoV-2 variants of concern contain a specific mutation ____, which results in enhanced binding affinity to _____, which cleaves spike + involved in virus internalization
Which type of evolution is this an example of?
D614G
TMPRSS2 (on host cell)
CONVERGENT evolution!!
Mutation ____ on the spike protein allows virus to bind tighter to human cells, making new variants more contagious
N501Y
True or False: E484K mutation may make it easier to re-infect someone who has been vaxxed
True
Why was omicron less able to cause disease?
- less efficient replication
- many mutations
True or False: Delta was associated with increased transmissibility and more severe disease
True
True or False: Coronavirus genome is slowly mutation, has relatively stable genome
True
Coronavirus has a proofreading mechanism, which means the mutation rate is lower than influenza and, therefore, subject to less __ ___
antigenic drift
True or False: While infected individuals can produce variants, most do not survive. Only a few virions go on to infect another person – therefore, populations change relatively SLOW during ‘normal infections’
True - bottleneck effect
IC patients do not clear infections - what does this allow for?
Continued selection for viruses capable of evading IR
Where do pathogenic viruses come from?
- Recombination or reassortment (Emergent Virus)
- Zoonoses *
- Disease Emergence
True or False: All severe coronaviruses trace recent evolutionary history to bats
True
___ ___: A primary pathology of COVID, in which there’s a combo of inflammation, development of thrombosis in lung capillary + systemically
Cytokine Storm
Which host response contributes to flu-like symptoms seen with COVID?
Interferons
True or False: Covid can suppress body’s ability to make interferons
True
