BIO 101 Test 1
Monkeypox has DNA as its genome. Once the supplies of vaccine are more readily available, would you expect that once immunized, people would have to get repeated boosters like for SARS CoV 2? Why or why not?
Unlike CoV 2, whose genome consists of viral RNA, Monkeypox has DNA. Therefore, it's polymerase that replicates genomes has the ability to proofread its copies before going through with the replication. So, no mutations will occur unlike viruses with RNA polymerase which can't proofread during replication.
Some viruses have an envelope. How is a virus envelope analogous to in an eukaryotic cell?
Virus envelope is analogous to a eukaryotic cell's cell membrane.
What characteristics of living organisms do viruses also have?
Viruses are made of proteins and glycoproteins like cells do. They have a genome but it isn't always DNA. They evolve
Which viruses are more likely to cause pandemics - Viruses with RNA genome or viruses with DNA genome? Why?
Viruses with an RNA genome are more likely to cause pandemics. Because viruses with RNA don't have the ability to proofread, it often results in genome mutations or errors. Sometimes mutations allow the virus to have selective advantage making it easier to spread and infect more people. Also, mutations delay the cure/treatment development.
As we discussed in class, influenza can undergo genetic shifts which often causes major pandemics. What is unique about influenza viruses that allows them to undergo genetic shifts?
We didn't talk about this as much this semester but remember a flu virus has 8 different pieces of its genome. Plus there are also swine flu and bird flu that also has 8 different pieces of its genome. Sometimes a cell (could be human but usually starts in swine or bird) is infected with 2 different flus (swine and human or human and bird) - they mix in cell so get new viruses that are part human/part bird or part swine/human — DANGER - new pandemic....that is what happened with 2009 H1N1 pandemic
Which pandemic was spread by mosquitoes
Zika 2014-5 and West Nile Virus
Define Zoonotic
a virus that transmits from animals to humans
What is the difference between attenuated, replication capable virus vaccine and an inactivated or killed virus vaccine? a. In terms of viral component of the vaccine? b. In terms of adaptive immune response?
a. Attenuated: Live virus is administered directly to the patient, able to replicate // It could have RNA or DNA genome - just the problem is that if RNA more likely to mutate and cause disease Inactivated: DEAD/Killed, unable to replicate virus is administered to the patient, cannot mutate // could have DNA or RNA genome b. Attenuated: both B cells and Tcells released - B cells release AB which will block virus from binding/entering cell; T cells, specifically cytotoxic T cells will attack and kill virus infected cells Inactivated: only B cells released (see above)
A monoclonal Ab recognizes and binds to one particular part of the spike protein and keeps it from attaching to cells. a. Why would this work as an effective anti-viral? b. If Monoclonal Ab 1 worked really well against the delta strain of SARS CoV 2, why would it not work on the Omicron strain or other strains currently circulating in the population?
a. This ensures that the spike protein can't bind to the cell so then it no longer has hosts to keep replicating and spreading to. b. Since the virus mutated the monoclonal Ab might not recognize and bind to the part of the spike protein that is necessary in order for it not to be able to bind to the cell. (YEP - Well said —that is exactly why they aren't using the monoclonal Ab anymore as treatment - not as effective in stopping binding of Spike to cells because so many mutations in Spike)
Define Vector
intermediate organism, to be transmitted from one type of host to another (ex. mosquitos)
Pandemic spread by aerosols
- 2009 panH1N1 - SARS CoV 1 2003 - MERS
What are two reasons that SARS CoV 2 is still spreading in US and world? Briefly defend your two reasons.
- As the virus spreads, genetic mutations accumulate over time. Mutations increase the virus' ability to spread and adapt to its environment. In other words, some characteristics of viruses are changing all the time, and this makes it impossible for any country to catch up. - Some regions, such as Africa, are too economically disadvantaged and have such poor medical infrastructure to have access to vaccines, or abilities to store, administer vaccines. At the same time, the huge population in some countries also leads to many patients who cannot be treated in time due to the insufficient number of medical staff, and the infection cannot be controlled in time. - travel contributed to spread - as symptoms were minor, people traveled and spread virus - For US - Lack of strong national consistent public health message and strong emergency response - lack of masks, preventive measure for healthcare professionals , low % of vaccination allowed virus to continue to spread and mutate.
Pandemic transmitted by unprotected sex
- HIV - Ebola West Africa 2014-6
This pandemic is caused by a virus has the most errors in the genomes and is the most genetically diverse
- HIV - West Nile Virus - 2009 panH1N1 - Nipah - SARS CoV 1 2003 - Ebola West Africa 2014-6 - Zika 2014-5 - MERS
What characteristics of living organisms do viruses share with our cells?
- Made in cells (but not necessarily made up of cells) - Evolution (especially RNA viruses) - Adaptation - Genetic material - The ability to reproduce (but only if in a cell).
Which pandemic is linked to bats (either direct contact with bats or bat products or via other animal host)
- Nipah - SARS CoV 1 2003 - Ebola West Africa 2014-6 - Ebola DRC 2018 - MERS
Which pandemic(s) is zoonotic?
- West Nile Virus - 2009 panH1N1 - Nipah - SARS CoV 1 2003 - Ebola West Africa 2014-6 - Zika 2014-5 - MERS - Ebola DRC 2018
Based on what you have learned about viral pandemics, what are the top 3 contributing factors to recent and future viral pandemics?
- misinformation/mistrust - travel - disparities in healthcare systems
List 3 characteristics of all living organisms
1. Cellular organization (have cells) 2. They can reproduce 3. They grow and develop 4. Homeostasis 5. Ability to adapt
Which pandemic linked to large hog farms in Mexico and import of swine from other countries
2009 panH1N1
In our cells, our genome which contains genes (information for making proteins) is in its own compartment, the nucleus, but ribosomes (that synthesize proteins) are in the cytoplasm. How does the information from the genome get to the ribosomes? Maybe a better way to ask this is: If DNA doesn't ever leave the nucleus, how is the information carried from the DNA to the ribosome?
A mRNA (messenger RNA) carries the information from DNA in nucleus to ribosomes in cytoplasm to make proteins.
There is a new viral outbreak on WFU campus. It is caused by the Demon Deac virus - anyone infected turns into the Demon Deacon after 3 weeks post infection. a. What mode of transmission would lead to a high infection rate on campus?
Aerosol transmission
What is the genome of all cells - bacterial or ours? How do viruses differ from cells in types of genomes?
All cells have a genome that is double stranded DNA - no exceptions. Viruses can have RNA or DNA as their genome - the RNA or DNA genome can be single stranded, double stranded (actually genome is part of how we characterize viruses)
Once the SARS CoV 2 vaccine was available, predict the outcome of the pandemic if 80-90% of population was vaccinated within the first month of vaccine availability.
Although the virus will continue to mutate in response to the vaccine, in the grand scheme of things the outbreak will be greatly reduced and fewer people will be infected.
Define Virus
An infectious agent that can only replicate/reproduce within a host organism. It is simple - made of proteins (capsid) and genome (RNA or DNA) and some have an envelope (phospholipid membrane outside capsid)
Define Reservoir
Animal host of a zoonotic disease (ex. bats, rodents, cows, pigs, sheep, swine)
Which of the following would more likely cause a pandemic that lasts years? Briefly, why? a. One that has 50% lethality and spread by bodily fluids b. One that has 2% lethality and spread by aerosols c. One that has 35% lethality and spread by ingestion
B
Each of the following statements describes a step in the replication of the SARS CoV 2. List them in the correct order that they occur in the human body. a. The virus releases its RNA genome into the cell b. Viral RNA polymerase helps copy the genome c. The Spike protein binds to a receptor on human lung cell d. The envelope of the virus and the plasma membrane of the cell fuse. e. New viruses travel to the cell membrane of the infected cell and are released outside of the cell. f. The virus RNA genome is used by cell's ribosomes to synthesize the viral proteins g. RNA genomes and viral proteins self-assemble into new viruses
C, D, A, F, B, G, E
All cells have _________ as their genome, but viruses can have ____________ and ____________ as their genomes.
DNA; DNA, RNA
T or F. The genome of SARS CoV 2 is copied by the cell's polymerase
False - our polymerase can only use DNA as template to make more DNA - No cell has an RNA polymerase so if virus needs an RNA polymerase it has to make it in the cell (using cell ribosomes)
What is one reason that polio virus has been detected in New York, London and Israel?
Fewer people are getting vaccinated, and children born during COVID-19 or through home births will not necessarily receive their vaccines. Additionally, the Salk vaccine only offers B cell protection because it is an inactive virus which would provide less immune protection for the circulating vaccine strain of polio.
Pandemic most closely related to chimps/non human primates virus.
HIV
Why is HIV so genetically diverse?
HIV is so genetically diverse because its RNA genome copies into DNA which is the most error prone process. It likely has also had time to become genetically diverse due to the stigma surrounding the virus. As well as the HIV virus was circulating in African populations before spreading to Europe and America.
How is a virus envelope like a cell membrane (plasma membrane)?
In a eukaryotic cell, the plasma membrane acts as the boundary made of phospholipids and proteins. These proteins act as pores to help move things in and out of a cell. Similar to a plasma membrane, the envelope acts as an outer wrapping of a virus. An envelope is formed when a part of the host cell membrane envelops the virus, forming an outer layer. Envelope is made of phospholipids and proteins just like cell plasma membrane
The Demon Deac virus continues to spread beyond WFU into the Winston Salem community and beyond. You have been tasked with determining if the virus is mutating and if so, how does the genome sequence compare with the original virus. You can also use the sequence data (A, T, G, Cs) to determine how the virus has spread between individuals. Examine the data below (SEE SG): In the column labeled # of mutations compared to patient 0, indicate how many mutations occurred in each patient. Based on this data, how did the virus spread among this group of individuals?
It started from Patient 0, then it spread to Patient Y, then it spread to Patient Z and finally it spread to Patient x.
What is the most likely origin of SARS CoV 2? Based on data we discussed in class, was it a lab leak or zoonoses? Briefly, why?
It was a zoonose, because there is no evidence for the lab leak but for the wild animal market. There was evidence that wild animals at the seafood market were carrying the virus according to our discussion in class.
Which pandemic are humans infected via contact with camels
MERS
When physicians and nurses returned to the US after volunteering with Doctors without Borders during 2014-16 Ebola Outbreak, people in the US were fearful of being in the same room and breathing the same air with asymptomatic physicians and nurses. Based on what you learned about Ebola, was that a likely way for Ebola virus to spread?
No, Ebola spreads through bodily fluids. Though the asymptomatic people could have been carrying the virus (extremely unlikely), they should not be worried about breathing the same air. It does not spread through aerosol
There is a new viral outbreak on WFU campus. It is caused by the Demon Deac virus - anyone infected turns into the Demon Deacon after 3 weeks post infection. b. Tests have been developed to detect individuals that are infected - What would be the most sensitive test - PCR (genome), antigen (had been exposed), or antibody (been vaccinated or had infection)?
PCR - testing for genome is MOST sensitive test and detects lowest amount of virus component
What is one reason that monkeypox has become more widespread in recent years?
People stopped getting vaccinated against smallpox in the 80's, which is thought to be contributing to the recent rise in monkeypox cases. The smallpox vaccine is 85% effective against monkeypox, so individuals who have been vaccinated against smallpox would likely also be protected against monkeypox. Additionally, recent cases of monkeypox have presented as genital pain instead of a rash, so it may be harder to recognize
There is a new viral outbreak on WFU campus. It is caused by the Demon Deac virus - anyone infected turns into the Demon Deacon after 3 weeks post infection. c. If this virus infection were to become a pandemic, is the virus genome more likely DNA or RNA? Why?
RNA, more strains due to there being mutations, which will require more vaccines, and thus will result in it being harder to combat. This is the case because mutations with a selective advantage will make the virus more infective and those strains will spread across the viral population.
What do all viruses require from a living cell?
Ribosomes (all viruses require cell ribosomes to make their proteins - big part of reason why they need a cell to replicate/reproduce)
Which pandemic was not actually a pandemic
Swine Flu 1976
You have been hired by CDC to advise them on future pandemic preparedness. Based on SARS CoV 2 pandemic response and monkeypox response in US, what would be your # 1 best advice to be better prepared for future pandemics?
Take the virus seriously before it spreads and becomes a pandemic (contact tracing, surveillance, etc... when one case arises), immediately optimize vaccine responses and development, distribute vaccines early on so that all countries are prepared, invest in healthcare in economically deprived countries, invest into education of diseases and viruses and encourage good hygiene practices, before pandemics begin, assess risks and gaps in healthcar
A friend of yours has refused to get the flu vaccine because it isn't natural - It is not like your own adaptive immune response. What would you tell them to explain to them how vaccines are natural?
The flu vaccine is an inactivated whole virus that injects virus into your body, so that when exposed to your immune system, you will naturally create antibodies. It mimics what happens in an infection without making you sick - it mimics a primary adaptive response so your body has memory cells — then when it is flu season and you get exposed to flu virus - memory kicks in fast and swift and no actually flu infection/disease - which is a secondary adaptive response. Plus body's B cells make Ab that bind to virus to virus can't enter cells - virus key is blocked by ab so can fit in cell's lock.
How does SARS CoV 2 "know" that it has found the cell that will allow reproduction of the virus?
The protein spikes (also called crowns) on the virus scan for the right cell to latch onto. Once they find the human cells, they latch and the plasma membrane of cell fuses with envelope (like a mini plasma membrane) so viral RNA genome gets in and hijacks the cell.
Why is a vaccine the most effective prevention for a viral infection?
The vaccine mimics the primary exposure to pathogens, so B cells or T cells are made specific to the pathogens proteins. When encountering the actual pathogen the memory cells will respond much faster and have a higher respons
Once the RNA genome of SARS CoV2 gets into our cells, what happens next?
The virus can "take over" cellular ribosomes to make spike proteins and RNA polymerase. The RNA polymerase transcribes the RNA genome. These proteins and RNA genome self-assemble into a full virus which is then able to leave the cell and infect other hosts. The virus may also prevent the cellular ribosomes from making its own proteins.
Why are antibodies effective against SARS CoV 2 infection?
They attach to the spike on Sars Cov 2. Since the spike protein is what attaches to human cells it allows the virus to enter our cells. When this entrance is blocked, the infection is prevented.