The Science Behind the COVID-19 Pandemic
A diverse group of scientists and medical professionals are working to understand the COVID-19 outbreak. This includes epidemiologists who study the distribution, origin, and control of diseases like COVID-19. Also, geneticists and microbiologists have been vital in identifying and genetically sequencing the genome of SARS-CoV-2, the coronavirus that causes COVID-19 disease.
In this activity, you will learn important attributes of both SARS-CoV-2 and COVID-19, in addition to better understanding the theoretical framework of “flattening the curve,” the effort to slow the transmission of the virus.
Learning objectives:
- Describe the general features of the SARS-CoV-2 virus and how it infects cells.
- Summarize the pathology of COVID-19.
- Utilize models to understand and assess the impacts of different variables on rates of transmission and death.
- Explain how social distancing can “flatten the curve” and why this is important to community health.
1) Watch this 12-minute video titled “COVID-19: A Visual Summary of the New Coronavirus Pandemic”:
https://www.youtube.com/watch?v=jWMUBouaqb0. (Note: this video was produced in mid-March and some information has potentially changed due to the constantly evolving nature of the pandemic). Answer the following questions based on the video:
a) What does COVID-19 stand for?
b) Compare the mortality rate between the seasonal flue (influenza virus) and the virus that causes COVID-19.
c) What is the mean incubation period for COVID-19? What does this mean?
d) Why is a large spike in the number of daily infections a particularly bad thing?
2) Review the following infographic titled “How Coronavirus Hijacks Your Cells.”
https://www.nytimes.com/interactive/2020/03/11/science/how-coronavirus-hijacks-your-cells.html. (Note: you may be required to create free account with NY Times to view the content; access to NY Times is currently free in response to the COVID-19 pandemic). Answer the following questions based on the information in the infographic:
a) Summarize how SARS-CoV-2 enters a cell.
b) How is the virus destroyed?
3) Review the following infographic titled “Bad News Wrapped in Protein: Inside the Coronavirus Genome”.
https://www.nytimes.com/interactive/2020/04/03/science/coronavirus-genome-bad-news-wrapped-in-protein.html
(Note: you may be required to create free account with NY Times to view the content; access to NY Times is currently free in response to the COVID-19 pandemic). Answer the following questions based on the information in the infographic:
a) The graphic doesn’t define “genome”. What does this term mean?
b) Compare genome sizes between SARS-CoV-2 and humans.
c) In about 2 sentences, provide an overview of what is encoded by the SARS-CoV-2 genome.
d) SARS-CoV-2 is often described as novel, meaning that it is a new form not previously encountered by humans. Some of this novelty arises from what the infographic calls “an insertion of 12 genetic letters.” What is the significance of this particular change in its genome?
4)
Watch the 8-minute video, “What happens if you get Coronavirus” (https://www.youtube.com/watch?v=5DGwOJXSxqg
)
to get an appreciate of the biology of COVID-19 infection. Answer the following questions based on the information in the video.
a) The ribosomes in an infected person’s cell are used by the virus to do what? What is the overall importance of this?
b) Describe the connection between COVID-19 and pneumonia.
c) Summarize the biology behind how a potential vaccine would provide protection against SARS-CoV-2.
5) Dr. Keith Mortman from George Washington University shows how physicians can utilize a computerized topography (CT) scan to create a stunning 3D image of a COVID-19 patient’s lungs. Watch this 2-minute video (https://www.youtube.com/watch?v=HWn-pGf4B-M) and answer the following question.
a) Is COVID-19 similar to the seasonal flu or typical pneumonia? Briefly discuss.
6) Epidemiologists study how diseases move through populations. These scientists look at many variables such as transmission rates and the nature of the pathogen, and they use this information to design countermeasures to halt the spread of the disease. Watch this 8-minute video, titled “What This Chart Actually Means for COVID-19”(https://www.youtube.com/watch?v=fgBla7RepXU). Answer the following questions based on the information in the video.
a) The video shows two curves on a graph, one with a tall spike and one with a flatter and longer curve. If both curves represent the same amount of people getting infected, why is the flatter curve ideal?
b) Diseases like COVID-19 can spread by exponential growth, but exponential growth is not an entirely intuitive concept. Using the lily pad example, the video indicated that lilies would fill their pond in 60 days by reproducing a constant rate. On what day is the pond 1% full? On what day is it 50% full? How does this help explain the “paradox of pandemics” mentioned at the beginning of the video?
c) Summarize how Philadelphia and St. Louis reacted differently during the 1918 flu pandemic and the consequence of these differences.
7) Epidemiologists use models to simulate how disease might spread throughout a population. To better understand this process and how social distancing affects transmission rates, use the resource titled “Why Outbreaks like Coronavirus Spread Exponentially, and How to “Flatten the Curve”” (https://www.washingtonpost.com/graphics/2020/world/corona-simulator/) and answer the following question.
a) Towards the end of the article, they summarize each of the 4 simulations in a single graphic. In particular, think back to the simulations that produced the two graphs on the right, “moderate distancing” and “extensive distancing.” Describe how the simulations were different and how the outcomes/graphs were different.
8) Lastly, “Outbreak” (https://meltingasphalt.com/interactive/outbreak/) is an interactive resource that enables users to change the variables of a simulation. Models like this are simplifications of complex real-world scenarios. Nevertheless, they are still useful in understanding the role that each variable has in the epidemiology of a disease like COVID-19. Work through the various interactive simulations, which get progressively more sophisticated, and answer the following questions.
a) For the “Number of Encounters” simulation, if you keep travel radius at 10 and transmission rate at 0.3, what is the largest number of encounters per day that will result in less than half of the population getting infected? (On the graph directly below, you can use “recovered” at the end of simulation to determine what percentage were infected overall.)
b) In the “Hospital Capacity” simulation, if you keep hospital capacity at 5% and input fatality rate at 3%, what is the fatality rate at the end of the simulation? Why does this differ from the input fatality rate? In other words, if a disease typically kills 3% of people it infects, why might we get an actual death rate that differs from that?
c) For the “Flatten the Curve” simulation, describe what it took for you to flatten the curve?
d) Of the three scenarios below, which one is most likely to limit the COVID-19 outbreak? Defend your answer based on what you learned from the models.
i) 75% of US counties have enacted the following social distancing guidelines: schools are closed and mass gatherings like sporting events are banned, but parks and beaches remain open. People are encouraged to remain at home, but it is not enforced. The remaining 25% of US counties have no social distancing guidelines. About 30% of hospitals have purchased extra ventilators.
iii) Supply-chain issues mean hospitals cannot increase their capacity because of lack of ventilators and protective equipment for healthcare workers. Nationwide, schools, parks, and restaurants are closed, and mass gatherings are banned. About 90% of US counties have enacted guidelines that require people to stay at home and only leave for essential travel. People that are sick are required to self-quarantine.
ii) Most hospitals have increased their stock of ventilators. Nationwide, the hospital capacity has almost doubled. The government recommends that people practice social distancing, but it is not enforced. Schools and businesses remain open, but parks are closed and large sporting events are banned. The widespread use of masks has reduced transmission rates slightly.