final Flashcards
Phylogentics
tells us how old these viruses are
Immune memory
the immune system can remember the antigens that previously activated it and launch a more intense immune reaction when encountering the same antigen a second time
Variolation
, obsolete method of immunizing patients against smallpox by infecting them with substance from the pustules of patients with a mild form of the disease
immune escape
when the host immune system is incapable of responding against an infectious agent,
Antigenic drift
A subtle change in the surface glycoprotein (either hemagglutinin or neuraminidase) caused by a point mutation or deletion in the viral gene.
retro
“backward” describes the flow of information fromRNA back to DNA
lentil
“slow” describes the slow disease progression of the founding member of the genus
What are the 5 surface glycoproteins? ( in the order you put them on the photo)
- Fusion protein (F)
- Hemagglutinin (H)
- Polymerase (L)
- phosphoprotein (P)
- Nucleoprotein (N)
Polio eradication should be possible because…
- immunity to polio is lifelong
- we have highly effective vaccines
Poliovirus
An RNA virus that rearranges cell membranes and inhibits host cell translation while allowing its own genome to be translated
How many stereotypes does Poliovirus have? and how many vaccines do we have?
Three stereotypes and two vaccines
How does polio infect somebody?
- ingested polio replicates in oropharyngeal and intestinal mucosa
- Reaches the blood through the lymph nodes
- Excreted in feces over a period of several weeks after infection
- In some cases enters the central nervous system through retrograde axonal transport
Salk Inactivated Poolio Vaccine (IPV) Advantages
- No virus spread from vaccine
- No risk of vaccine related poliomyelitis
- Induces serum antibodies that protect against infection of the CNS
Salk Inactivated Polio Vaccine (IPV) ( one type of polio vaccine)
(disadvantages):
- Does not protect against infection of the intestine
- Vaccinated people can still be infected (but wont get poliomyelitis)
- Does not stop spread
- Needs to be injected (trained personnel)
- Cost (5x that of OPV plus cost of need needles and trained health care worker
“sabin” oral polio vaccine (OPV) advantages:
- Easy to administer without training (oral liquid)
- Cheap: sabin assigned his rights to the vaccine strains over to the WHO which greatly helped with low cost availability
- Replication in intestine induces mucosal immunity and prevents new infections
- Virus is shed ( “contact immunity”)
“sabin” oral polio vaccine (OPV) Disadvantages:
- Virus is shed : infection of immunocompromised hosts or naive populations
- But OPV can replicate in vaccine which means the virus can mutate
- Reversion to wild type in gut: non-attenuated strain can infect other people
Measle Virus/ what type of transmission is it?
Respiratory transmission ( reason why ots highly contagious because we all breathe eachothers air)
what does Measles virus cause?
Causes acute and chronic disease pathology as well as global immunosuppression (“immune amnesia”)
what impacted the measles virus vaccine delivery?
covid
Measles Pathogensis
:
Respiratory pathogen and gets in your lungs
Infects macrophages and dendritic cells in your lungs, those carry the virus to your lymph nodes and so when it gets to your lymph nodes it happy and sees what it’s favorite cell type to infect are , which are T and B cells, so your T and B lymphocytes
If a virus kills those pathogens, it causes immune amnesia , where essentially you wipe out memory against a lot of different pathogens
HIV ( what happened to your T cells?
Chronic infection, Infection and severe depletion of T cells
Is there immunosuppression with HIV if so, is there recovery from this?
severe , long term Immunosuppression (no recovery)
Is there immunosuppression with Measles if so, is there recovery from this?
Immunosuppression improves eventually (weeks to months to years)
what happens to your T and B cells with Measles virus?
- Less severe and your T and B cells regenerate
- Depletion of B cell memory
Dengue and Zika virus are transmitted by?
mosquito vectors
What are antobides can in some case enhance dengue virus infection? ( 4 of them)
- DENV 1 (RED)
- DENV 2 ( BLUE)
- DENV 3 (GREEN)
DENV 4 ( YELLOW)
RSV( respiratory syncytial virus)
- respiratory pathogen
what ages does RSV affect?
young and old
what was the key to developing a vaccine for RSV?
Rational design of the RSV F glycoprotein to elicit ‘good’ antibodies was the key to development of a good vaccine
How can vaccination for RSV help benefit mothers and their new borns?
Vaccination of mothers or antibody therapies can protect newborns (the most susceptible to severe outcomes from RSV infection)
Why did the RSV endure many challenges when creating a vaccine?
The reason why this vaccine endured many challenges was because the old vaccine caused these apparent immune complexes to form in the lungs of babies, which was really bad
what is glycoprotein?
Elicit only good antibodies that can be highly protective and we don’t make other antibodies that can actually be harmful
what happens when a mom who is prego is vaccinated with the glycoprotein?
If a mom is vaccinated , they’ll actually pass those good antibodies to their babies and protect them from really severe cases. ( lasts 6 months to a year)
Can someone get reinfected with RSV
YES
Influenza Virus 1can infect what host?
avian and mammalian hosts
HA and NA glycoprotein are recognized by…?
The HA and NA glycoprotein are recognized by antibodies , NA is the target of the one antiviral drug
what can reassortment of genome segments lead to..?
an lead to viruses with gene segments from different flu vaccines that infect the same cell with a big impact on influenza evolution and spread
what has had a major impact on the influenza evolution?
“reassortment” is the separation on genes on different segment and it has had a major impact on the influenza evolution
what needs to happen in order for reassortment to happen?
a single cell has to be infected by both viruses. They will essentially infect the cell and genome segments form both will be replicating.
is HA or NA more dominat of a glycoprtiein?
HA
what influenza strain is the cause of all of the flu pandemics?
Influenza A
what happened in 1918 with Influenza 2?
1918 flu was not a reassortment was actually just a bird virus completely that jumped into the human population
why do we need to change the influenza vaccines every year?
- there can be changes in the glycoproteins and that’s why we need a new vaccine each time)
- The antigen , HA, antigen in the virus is changing slowly over time and such that peoples immune responses generate to the virus so in the same time next year you won’t be able to predict from the virus that going to be present the next time around
what is cross protective immunity?
Individuals born in early to mid 1880s had seen to H1 flu before
why is HA important in virus evolution in terms of shift, drift, and vaccination? ( 3 reasons)
- HA mediates receptor binding
- HA is the major target for antibody target for antibody recognition
- Virus mutation leads to antibody/immune escape
Antigenic drift:
- Point mutations in HA and NA is existing human variants
- some cross protection
- is selection for escape from neutralizing antibodies
antigenic shift
- little cross protection
- up to 30% of the population gets infected
- global pandemic
what is HPAI?
Highly pathogenic avian influenza
where do we see HPAI in?
wild birds and mammals
what do genomes show us?
Genomes shows us the fossils of ancient infections, such as a retroviruses related to HIV in lemurs
why are retroviruses retro?
Retroviruses are “retro” because they convert their RNA genomes into DNA
- Retroviruses inert their genome into the genome of the host cell (integration)
- Retroviruses become a permanent part of the cells they infect
what needs to happen in order for something to become endogenize?
In order for something to become endogenize it has to infect the germ line, which is whats being shown here in the case of sencetin as an example, this captured thing in the genome is actually now sued in a different way by our cells as this sensetingne , then HIV again
HIV 1 is..
Retrovirus (RNA virus that reverse transcribes its genome into DNA) that infects immune cells
what does HIs infect?
infects immune cells: (T cells, macrophages)
HIV is a retrovirus because : ( 4 reasons at least name 2)
- Have small RNA genomes
- Use an enzyme called reverse transcriptase to make DNA copy of their RNA genome
3.DNA copy of the viral genome inserts itself into the host DNA genome (through the process called integration)
4.Become permanent part of the cells they infect
what is HAART?
Highly active antiretroviral Therapy
what is the acute and chronic infection look like in HIV
loss of CD4 T cells cells during chronic infection leads to severe immunosuppression (opportunistic infections)
