Coronavirus (COVID-19) - What You Should Know

The outbreak of COVID-19 (coronavirus) has prompted many people to take precautions to keep themselves safe. We asked Dr. Justin Clark, PhD to answer some of our key questions that are on people’s minds right now.

Editor's note: This article was initially posted during the summer of 2020 and has not been updated to reflect the current scientific discoveries of COVID-19. For more up-to-date information, please refer to the Centers for Disease Control and Protection website. 

This is Part 1 of our COVID-19 series. Please see the other parts below: 

  1. Can Microwaving Mail Kill the Virus? Can You Get COVID-19 Twice? Answering Your Questions about COVID-19
  2. What's the Safest Way to Shop? Are Certain Blood Types at Higher Risk? Answering Your Questions about COVID-19
  3. The What We Know Now: The Latest Updates to Your Covid-19 Questions - Q&A with Gabriel Espinoza, Md. What Disinfectants Kill Covid-19? What Is the Progress of a Vaccine? Are Cloth Masks Effective? Are We Experiencing A Second Wave? Are Kids at Risk?

Picture of Dr. ClarkPicture of Dr. Clark

Dr. Clark’s Background:

Dr. Clark graduated with a B.S. in Biology from the University of North Carolina and was awarded a Ph.D. in Integrative Molecular and Biomedical Sciences from Baylor College of Medicine. He has researched bacterial and viral pathogens for over 10 years. All opinions are his own. 

Our QNL staff interviewed Dr. Clark to get his candid thoughts about the spreading virus. Below are his honest and transparent responses.

QNL: What is coronavirus or COVID-19?

Dr. Clark: “Coronavirus” is a bit of a misnomer because that term is really too broad because it refers to viruses that are members of the entire coronavirus family of RNA viruses. This is analogous to how humans, chimpanzees, and gorillas are all called members of the “great ape” or “hominidae” family of organisms. Obviously, humans are quite different from chimpanzees.

Coronaviruses are distinguished from other groups of viruses by their “crown” or “corona” of a club-shaped surface protein (hence the name!).

Within this family of coronaviruses, there are several viruses known to cause respiratory infections in humans. Most are mild, but some, like SARS or MERS, can be severe. The current outbreak is caused by a coronavirus known as SARS-CoV-2, or SARS-associated Coronavirus 2. And to make this really confusing, the disease that is caused by SARS-CoV-2 is called COVID-19, which stands for Coronavirus Disease 2019. Informally, people use coronavirus, COVID-19, SARS2, and SARS-CoV-2 somewhat interchangeably.  

QNL: What is the source of the virus?

Dr. Clark: We don’t know the exact origin of the virus. We do know that this novel animal virus somehow switched hosts into humans, probably somewhere near Wuhan, China in the Hubei province in November or December of 2019. However, we aren’t sure what animal it came from, or exactly where in Wuhan it started. It was first reported that it came from the Huanan seafood market in Wuhan, but roughly one third of the first 41 cases were not exposed to that particular market.

The virus probably came from bats since most of its genetic material is very similar to a coronavirus found in bats. However, a piece of the protein that makes up the “crown” and binds to the host is more divergent from the coronaviruses that we typically know. This suggests that there is an unknown intermediate host. Researchers at Baylor College of Medicine were the first to locate a potential source for this most divergent piece of protein when they found a match from a coronavirus found on a pangolin (an Asian mammal that is covered in scales, similar to an armadillo). But it is still unclear whether pangolins really are the intermediate hosts and what chain of events led to this virus transferring from animals to humans.

QNL: Is coronavirus the same as SARS and MERS?

Dr. Clark: SARS and MERS are caused by coronaviruses that are closely related to SARS-CoV-2. However, all three have distinct biological and clinical characteristics. The most notable difference is the fatality rate, which is roughly 10% for SARS and 35% for MERS compared to the WHO’s current estimate of 3.4% for SARS-CoV-2.

QNL: How is the virus spread?

Dr. Clark: It is thought that SARS-CoV-2 primarily spreads much like influenza: either through droplets expelled during a cough or sneeze, or by being transferred to your nose, mouth, or eyes from your hand that has touched a contaminated surface. There is evidence to suggest that the virus can also spread through an oral-fecal route similar to “stomach flu” and viral diarrheagenic diseases. However, we are unsure how frequent oral-fecal transmission is.

Box of tissuesBox of tissues

QNL: What are the common symptoms associated with the virus?

Dr. Clark: The main symptoms that most governments are warning people to look for are:

  1. Fever
  2. Cough
  3. Shortness of breath

This aligns with a study from China’s WHO branch of 55,924 COVID-19 cases in China, where the 5 most reported symptoms are fever (87.9%), dry cough (67.7%), fatigue (38.1%), sputum production (33.4%), and shortness of breath (18.6%).

It is believed that at least 80% of all cases are mild and require no medical attention, so many people may not realize they have been infected.

(QNL Update: The CDC lists fever or chills, cough, shortness of breath, difficulty breathing, fatigue, muscle and body aches, headache, new loss of taste or smell, sore throat, congestion or runny nose, nausea or vomiting, and diarrhea among the main symptoms. More information about symptoms of COVID-19 can be found here.)

QNL: What is the incubation period of the virus?

Dr. Clark: The incubation period appears to generally be between 2 and 14 days, with half of infected people showing symptoms by day 3. There have been some reports of incubation lasting up to 24 days, but this is not common. 

QNL: Does the virus survive on surfaces and if so, for how long?

Dr. Clark: With SARS-CoV-2, we don’t have much first-hand knowledge at this time. But we have been estimating based on what we know from other coronaviruses. Under ideal conditions, these viruses can remain viable for up to 9 days. But generally, the virus lasts only 4 to 5 days on most surfaces.

The only study I know of specifically looking at SARS-CoV-2 was just released in early March by researchers at the NIH, CDC, UCLA, and Princeton. Their results suggest that the low levels of infectious virus can be found after 8 hours on copper, 24 hours on cardboard, and 48 hours on plastic and steel.

Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents

Aerosol and surface stability of HCoV-19 (SARS-CoV-2) compared to SARS-CoV1 

QNL: Are there certain populations at a higher risk than others?

Dr. Clark: Like the flu, the elderly are at higher risk. Preliminary data out of China shows a mortality of 14.8% for people over 80, 8.0% for people 70 to 79, 3.6% for people 60 to 69, and 1.3% for people 50 to 59. Ultimately, around 80% of deaths there were from people over 60. However, unlike the flu, this virus does not appear to cause serious disease in children as often as it does in adults, with no deaths in children under 10 being reported in China. Data coming out of Italy the last few weeks seems to match what China was reporting for the most part.

People with certain pre-existing conditions are also at increased risk. The top 5 pre-existing conditions are: cardiovascular disease, diabetes, chronic respiratory disease, hypertension, and cancer.

Washing your hands frequentlyWashing your hands frequently

QNL: How can people protect themselves from getting the virus?

Dr. Clark: The two most common ways to be infected are thought to be either being exposed to infectious droplets from a cough or sneeze, or by touching a contaminated surface and then touching your face.

Droplets are not thought to stay suspended in the air long which means you probably have to be near someone that is coughing or sneezing to be exposed. To lower your risk of this, there are some commonsense precautions you can take including avoiding sick people, avoiding crowds, and keeping a few feet distance between yourself and others.

The best way to avoid infecting yourself from a contaminated surface cannot be repeated enough: please wash your hands. The simple act of washing your hands for 20 seconds is probably the biggest single thing you can do to protect yourself from this and other respiratory viruses. You should also practice not touching your face. But most people have trouble with this because we touch our faces up to two dozen times an hour without even realizing it.

QNL: Does wearing a mask protect people from getting the virus?

Dr. Clark: There are two different types of disposable masks that people commonly wear: surgical masks and respirators. Surgical masks are the ones that are composed of a piece of paper with attached cords so they can hang from the ears. These masks are designed to protect the environment from the wearer and offers limited, if any, protection against viruses.

A disposable respirator can protect a person from the virus that is transmitted via aerosols, but that statement comes with a lot of caveats. First, the respirator must be fitted properly. This seems like a simple suggestion, but not having a good seal negates most of the benefit you could receive from the respirator.

Second, you have to treat the respirator as being contaminated whenever you take it off. This means not hanging it around your neck or setting it on your desk beside your lunch.

Third, resist the urge to fidget with it, because you may end up touching your face even more and increasing your risk.

Fourth, a mask is not going to make you invincible to the virus, so you should not become complacent while wearing it.

Because of these obstacles to a respirator’s effectiveness, the benefit it has to a member of the general public is probably low. Especially when you consider that the virus may still enter through the eyes, which a respirator will do nothing to protect. But for healthcare workers who are trained and properly fitted for respirators, this type of mask is very effective when used with other protective equipment. Therefore, the Surgeon General and the CDC are asking the public not to horde masks since we are currently experiencing a shortage and it is vitally important that healthcare workers be protected.

It is also important to note that both surgical mask and respirators do help prevent someone who is infected from spreading the virus though. So, if you can, you should wear one if you are showing symptoms of COVID-19 or any other contagious respiratory illness.

QNL: Should people avoid events where there would be contact with large amounts of people?

Dr. Clark: Currently, the chances of catching SARS-CoV-2 at a social event that is not in an area with confirmed community transmission are still very low. But this may change as the virus becomes more prevalent. It is important to listen to expert recommendations for your area to understand how much potential risk there is.

However, if you are in a high-risk group (over 65 or have pre-existing conditions), the CDC is recommending that you limit your exposure to crowds, air-travel, and cruises as much as possible.

QNL: What testing is available to confirm someone has the coronavirus?

Dr. Clark: The frontline test being used by all governments is an assay called real time Reverse Transcriptase Polymerase Chain Reaction, or rRT-PCR. Basically, this method can be used detect a specific genetic sequence in in real-time. With the CDC’s COVID-19 kit, reagents are used to detect three specific SARS-CoV-2 sequences in nose and throat swabs. If SARS-CoV-2 genetic material is found to be present in a swab, the material will be interpreted as positive. However, this test does require expertise to interpret it by using advanced equipment.

Some countries are starting to experiment with other methods of testing, but none are being widely used yet as far as I know.

(QNL Note: Testing for COVID-19 has changed as the situation develops. Please reference this website for updated testing information.)

QNL: What should people do if a family member living in the same household tests positive for virus?

Dr. Clark: The CDC has a great website for this.

Their basic recommendations are:

  1. Separate the sick individual from other people and pets as much as possible.
  2. The infected individual should wear a facemask if possible.
  3. Cover cough and sneezes.
  4. Wash hands often and immediately after coughing or sneezing into them.
  5. Avoid sharing items between infected and uninfected individuals.
  6. Clean and disinfect “high-touch” surfaces every day.
Young hands holding elderly handsYoung hands holding elderly hands

QNL: What preventative measures are there? Any work on vaccinations?

Dr. Clark: The best preventative measures we have right now are containment and social distancing. There is currently no medication that has been scientifically proven to be effective against COVID-19, but there are several candidates that are already in clinical trials. These include an anti-Ebola drug (remdesivir), an anti-Malaria drug (chloroquine), and nitric oxide gas.

Dozens of biotech and academic labs have already announced plans to work on a SARS-CoV-2 vaccine. A few have already moved to clinical trials. However, it will be over a year before they are ready to start administering a vaccine if one can be proven to be safe and effective, so it will not be helpful in stemming the current pandemic. 

QNL: Should people be concerned about shipments coming from China?

Dr. Clark: This is a fair question given that some coronaviruses appear to be viable on surfaces for days. However, the CDC believes that it is very unlikely to get infected by items in the mail that have been shipped for days or weeks at ambient temperature. They note that there have not been any cases of COVID-19 being spread through the mail. Most shipments from China can take up to two weeks by ship to reach the U.S., so there is likely no need to worry about those. Even though the virus may last days under ideal conditions, air-shipments are not ideal conditions. If that isn’t enough to ease your mind, there is also the study I mentioned earlier that showed that the virus can only survive for about 24 hours on cardboard. So, if you’re concern, you can use a disinfecting wipe on the outside of the package or simply quarantine it for a few days in a garage or closet.

QNL: How does this compare to the movie, “Contagion”?

Dr. Clark: Contagion was a movie (2011) based on a fictional account of an outbreak of a dangerous disease. This movie did a good job of showing how a novel and deadly airborne virus can spread and the challenges we would face if that were to happen. I did appreciate that "Contagion” included “science-y” graphs and figures that generally matched what the “scientist” was talking about. This is hardly ever the case in movies! Often the “scientist” will be talking about something completely unrelated to what is being shown on their projector/computer. They also used scientific jargon you would expect from scientists, such as “contact tracing,” “fomite” (inanimate objects that have come into contact with a pathogen), and “R0” (pronounced R-naught, how many people an infected person will infect on average).

But there are some glaring inaccuracies in the movie. The virus in “Contagion” spread a little too quickly, jumping from one person to another in seemingly as little as one day. In reality, it takes time for a virus to infect a host and then reproduce itself in high enough numbers to spread to others. The movie also didn’t really show how social distancing and public health measures could slow down an outbreak or that most people (70-80%) recovered from the virus.

The vaccine was also developed at an unrealistic pace. It would typically take more than a year to develop a vaccine – not 4-6 months as shown in the movie. And it would certainly take more than a positive result from one animal before we could be sure that the vaccine worked the way it was shown. This is because several things other than a working vaccine could cause a single animal to live.  Human error when exposing the animal to the virus would probably be the most likely.  Or it could just a random fluke—after all, not everyone succumbed to the virus so there is no reason to think it would kill 100% of the animals exposed.

Luckily, COVID-19 is not at all the same disease shown in “Contagion”. Unlike the movie, COVID-19 has a much lower estimated mortality rate, especially among young, healthy people.

QNL would like to thank Dr. Clark for his thoughtful contributions to this post.

Editor's note: We've published a new, informative Q&A with Dr. Clark answering your questions about COVID-19. You can read Part Two here. Part Three can be found here.