lecture 8 Flashcards
bovine H5N1 viruses are only 1 ____ substation aways from efficient binding human receptors ?
only 1 HA
what do highly virulent avian influence (H5N1) virus strains have at the HA cleavage site?
what does this permit?
–insertion of multiple basic AA
–cleave by expresses intracellular proteases—> allows it to be released from the cells and can infect many organs
what is a zoonosis?
what is a vector?
wha his the most common vector born viral disease?
zoonosis: speeds from animals to people
-can be direct
-or by a tick
vector: agent that transmits virus between hosts (arthropod), like mosquito, tick
-dengue
what is a reservoir host vs a dead end host?
reservoir– host species in which the virus is spread Amongst and can be spread
dead end host: infected directly or indirectly from reservoir but does not transmit the disease to others in the same services and IS not a reservoir
-ex: rabies, ebola
what does the ebola vaccine contain?
how does the ebola vaccine work?
-contains engineer VSV to express Ebola Virus spike protein –> live virus, gives protected immunity
-contains proteins Ebola needs to replicate in people
-recombinant VSV replicate and provides a source of Ebola antigens that generates an immune response
what is ebola?
what kind of virus is ebola?
-rVSV-ZEBOV–> replicated competent vesciular stomatitis virus
-VSV is a - sense RNA
-replicates in people but does not cause disease in us
-rhabdovirus
what did the dengue virus vaccine show ? when is it only recommend?
-increases risk of hospitalization for seronegative vaccinated people who are infected with serotype 3
-those who have been infected with dengue so they don’t get ADE
what is the role of bats in human diseases?
what kind of immune system do they have?
reservoir for several zoonoses–> rabies, SARS, ebola, MERS
-when bat virus ended up in people, it is beloved that additional species serves as an intermediate host
-their immune system selects for robustness in viruses, which gives rapid IFN response
what factors contribute to or control dengue spread?
control: can be limited by measures that decrease misquitos
speed: reduction of water sanitation
what is common among flaviviruses?
-dengue virus sero cross reactivity drives antibody dependent enhancement of infection with zika
what is zika transmitted by ?
Aedes qegypti
what is ADE?
why does it happen?
how does it initiate??
what does host immune response aid with?
–people getting re infected with Dengue have worse disease when they are infected then they did the first time
– antibody binds to a virion, which then it allows the virion to associate with its target cell because Ab interacts with the Fc receptor
–can initiate replication in cells that engulf the Ab: virus complex
-aids with replication in this case!!
what can one flavivirus infection promote? example?
can promote ADE for the next
-ex—-> zika follows dengue
Note that viruses previously recognized to cause cervical cancer have recently supplanted
smoking as a major cause of head and neck cancers.. which ones?
HPV serotypes causes both
what properties acquired during the evolution of a virus in a host can make that virus a variant of cancer?
if they are more contagious, cause more severe disease, and are more or less sensitive to immune response
what conditions are necessary before a virus can successfully replicated in a new host?
–must be able to complete replication cycles in the new host
-must be able to use new host versions of host machinery it requires
- must be able to evade any restriction factors in the new host
what does CoV2 contain and what is it incompatible with?
contains FCS that is incompatible with bat
when are variants concerning?
why is omicron so contagious, what does it show mutations in?
–if it is contagious, causes more disease, or blunts immune response
– S1 subunit of the spike protein
–could have shifted to use only cleaved ACE2
what is the 6th most common type of cancer worldwide?
head and neck squamous cell carcinoma (HNSCC)
–HPV has been recognized as a factor for HNSCC
