Simone Harvey @solistens put together this brilliant summary on COVID-19 to help folks who are still struggling to connect the dots.
1. What is COVID-19?
In COVID-19, ‘CO’ stands for ‘corona,’ ‘VI’ for ‘virus,’ and ‘D’ for disease. Formerly, this disease was referred to as “2019 novel coronavirus” or “2019-nCoV”. The name of the actual virus is “Sars-CoV-2.” There are many types of human coronaviruses including some that commonly cause mild upper-respiratory tract illnesses. Severe Acute Respiratory Syndrome (SARS) and Sars-CoV-2 are related to each other genetically, but the diseases they cause are quite different. However, there are many types of corona viruses. Coronaviruses have caused two other recent epidemics – severe acute respiratory syndrome (Sars) in China in 2002-04, and Middle East respiratory syndrome (Mers), which started in Saudi Arabia in 2012. In both cases, work began on vaccines that were later shelved when the outbreaks were contained.
2. What does symptomatic/asymptomatic mean?
There are symptomatic (you can tell they have it: coughing, fever, etc.) and asymptomatic (you can’t tell they have it) folks with the virus. Being asymptomatic only means you’re not displaying or feeling any symptoms; you can still infect other people. Being asymptomatic means you will never develop symptoms. Being pre-symptomatic means that you are not showing any symptoms yet but will develop them later.
3. Why are some people asymptomatic?
We don’t yet know why some people are symptomatic or asymptomatic. The reason may be genetic or environmentally based or both. The latest number I read was somewhere between 25-50% of infected are asymptomatic, depending on who you ask. Some proportion of asymptomatic folks are actually just not sick YET (i.e. pre-symptomatic). There are also some articles that say your susceptibility is influenced by blood type. However, this research has not been peer-reviewed or published in a medical or academic journal, which means other experts in the field have not analyzed its research methodology, citations or significance. That means, for now, it is a hypothesis (or a GUESS), not fact. It appears that most children are asymptomatic but as you now know that doesn’t mean they can’t get you sick.
4. How do you know if you are in the symptomatic or asymptomatic group?
You don’t. Can you get a test that tells you which group you are in? No, tests confirming whether you are immune to the virus — identifying and measuring the COVID-19 antibody — have not been developed yet but I believe are underway. The only tests we have so far are those that confirm you have COVID-19 when you already have it.
5. What is an incubation period?
Viruses are typically spread before a person has any symptoms. The time period from when you first contract it (get it) to when you exhibit symptoms is called the “incubation period.” It’s the time the virus infects your cells and replicates inside of you without you noticing anything. This coincides with when the so-called viral load — the amount of virus being emitted from an infected person’s cells — may be the highest. In other words, when you are most infectious. For COVID-19 it is ~5 days. That means you could have it for 5 days before you display any symptoms. If you are asymptomatic (showing no symptoms) you will never display any symptoms. This is when you infect other people, unknowingly.
6. If there hasn’t been a case in my community, I should be ok, right?
No. The only way we know who has it and who doesn’t is if EVERYONE is tested. We neither have enough tests nor do we have tests that are always effective. Plus, you could get tested today and get infected tomorrow but someone who hasn’t been tested yet. The virus spreads very rapidly due to the estimated number of asymptomatic and untested people so you don’t know how far the virus has reached. And because of the incubation period you will not find out until much later.
7. The numbers of infected people published are a good reflection of where we are in terms of infections right?
No. The numbers published are a result of the number of people TESTED and the local, state governments BEST GUESS, the reality is likely to be 20-50x higher. If no one has been tested there are no known cases, get it?
8. Will a mask protect me?
A mask can reduce your likelihood of getting infected if you use it correctly. Think of the virus as blue paint people are spraying on you by sneezing, coughing or breathing on you. The size of the paint droplets make a difference but we only have guesses as to how much. Once the paint is on you and you touch it, you’ve been painted. So if it lands on any part of you, including your mask and you keep touching it, you’ve been painted. If you take off your painted mask and then touch your face, you’ve been painted, etc. Masks are pointless if you don’t avoid touching them, wash them or clean them when you get home.
9. What is a comorbidity?
The simultaneous presence of two chronic diseases or conditions in a patient. Conditions considered comorbidities are often long-term or chronic conditions. So for example, if someone has depression and heart disease or high blood pressure and diabetes. Some comorbidities often come together like high blood pressure, heart disease and diabetes. They are separate chronic conditions but are physiologically related because they influence each other. But that’s for another day.
10. What is the relationship between a comorbidity and COVID-19?
Among lab-confirmed cases of COVID-19, patients with any comorbidity yielded poorer clinical outcomes than those without. A greater number of comorbidities also correlated with poorer clinical outcomes. Translation: People who have additional chronic conditions like hypertension (high blood pressure) and diabetes are going to be sicker and have a harder time recovering than those who do not. This also means that if have other chronic conditions your likelihood of dying from the virus will be higher.
11. Is it true that only the elderly are most at risk for cover-19?
It is true that COVID-19 leads to hospitalizations and deaths more frequently in those who are middle-aged or older. But a significant number of otherwise healthy adults can develop a more severe form of the disease. Data from the Centers for Disease Control and Prevention found that among those age 20 to 44 with coronavirus in the U.S. from Feb. 12 to March 16, 14% to 20% were hospitalized. Although that’s a lower percent range than those above age 65, which ranges from 28.6% to 70.3%, it’s still a large chunk. 2-4% of those in the 20-44-year-old age category required admission to an intensive care unit. You don’t objectively know how healthy you are and how your body is going to react to this. Best not to gamble. Also, see #10, 11, 12.
12. What’s this “flattening the curve” business?
In epidemiology (the study of how disease spreads), the idea of slowing a virus’ spread so that fewer people need to seek treatment at any given time is known as “flattening the curve.” It explains why so many countries are implementing “social distancing” guidelines. Because of the asymptomatic folks, the 5 day incubation period and the lack of large scale testing, we are always only going to find out how many people are sick at a delay. The present will never be an indication of where we actually are. (See #7) Our healthcare systems can only treat so many people at once and so if more people need treatment than we have space or staff for we will overwhelm the system. That’s what’s happening in NYC. As a result, both folks who are very sick from the virus as well as other folks (car accidents, heart attacks, etc.) are less likely to get the care they need as fast as they need.
13. What’s all this talk about ventilators?
In the most severe manifestation of COVID-19, people’s ability to breathe is severely reduced to the point where they can’t breathe on their own or get enough oxygen to survive. If your organs don’t get a minimum amount of oxygen they will shut down. So in order to save people’s lives they are put on ventilators. Ventilators breathe for you if you can’t do it yourself. If the number of sick people, needing ventilators is higher than the number of ventilators available, we will have to start choosing who gets to live and who doesn’t based on ventilators available. This is a huge ethical issue. Some efforts to manufacture more ventilators are underway.
14. How does a vaccine work?
All vaccines work according to the same basic principle. They present part or all of the pathogen (disease causing agent) to the human immune system, usually in the form of an injection and at a low dose, to prompt the system to produce antibodies to the pathogen. Antibodies are a kind of immune memory which, having been elicited once, can be quickly mobilized again if the person is exposed to the virus in its natural form. As a result, you can fight off a new infection of a pathogen “known” to your system faster and with less damage. Kinda like “Oh I know what kinda bs this is and what to do about it.”
15. Why don’t we have a vaccine yet?
Vaccine development is a complex and drawn out process. About 35 companies and academic institutions are racing to create such a vaccine, at least four of which already have vaccine candidates they have been testing in animals. Clinical trials, an essential precursor to regulatory approval, usually take place in three phases. The first, involving a few dozen healthy volunteers, tests the vaccine for safety, monitoring for adverse effects. The second, involving several hundred people, usually in a part of the world affected by the disease, looks at how effective the vaccine is, and the third does the same in several thousand people. This process takes time and a lot of resources. Phase 3 alone typically lasts 1-4 years. So you see, it’ll be a while.
16. Once you have contracted the virus and have recovered you’re safe right?
No. We don’t yet know if people who have contracted the virus 1) can get re-infected by the same strain 2) are equally as vulnerable to another strain or 3) have any advantage as compared to someone who never had it. Once we can identify the COVID-19 antibody and test for it we will know who’s immune naturally (asymptomatic) or who has developed immunity as a result of having contracted the virus and recovering.
17. What is herd immunity?
Herd immunity is a form of indirect protection from infectious disease that occurs when a large percentage of a population has become immune to an infection, whether through previous infections or vaccination, thereby providing a measure of protection for individuals who are not immune. The tricky thing is that herd immunity requires that ~70% of the population have to have contracted and recovered from the virus (including asymptomatic carriers.) At such a high proportion of infected folks its likely that millions of people will die not just due to the virus’ mortality rate but also due to an overwhelmed healthcare system unable to care for the most severely ill in time no matter what they’re sick with.
18. What needs to happen for social distancing to relax?
Widespread testing to figure out who has it and who doesn’t
Definitive way to identify those who are immune either naturally or after recovery
Herd immunity but this would come at a cost of millions of people dying.
Any of these would allow for some people to go back into the public sphere safely.
*Doctors, biologists, biochemists, epidemiologists – feel free to correct if any of this is factually incorrect.