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
How do antibodies escape?
Mutations in the receptor binding domain of the spike protein reduce binding affinity of neutralizing antibodies to epitope on proteins
