Ask CU: The Science behind COVID-19 with Dr. Julie Phillips


To draw good conclusions in science, we normally look at the whole picture of the data. In the current case with COVID-19 we just don’t have all the pieces to the puzzle. Along with historians and economists, medical professionals and scientists will partner for years to come to understand the current global crisis. Many CU students have the potential to help study current events and change the future. The answers to the questions are written to the best of my knowledge (which unfortunately is coming from an incomplete picture).

How easily does the virus transmit?

Really easy! The more data that becomes available suggests that this virus has an incredibly high transmission rate. Epidemiologists measure the intensity of an infectious disease outbreak using the reproduction number represented as R0 (pronounced “R nought”). The formal definition of R0 is the number of cases, on average, an infected person will cause during their infectious period. COVID-19 had been compared to the flu, but the flu has a R0 between 1 and 2 while COVID-19 has a value somewhere between 2 and 3.5.

Why is soap the best way to protect against the virus?

Generally, a virus is composed of genetic material (DNA or RNA), a protein coat and sometimes a lipid envelope. In the case of COVID-19, there is a lipid envelope. Lipids like other lipids, and soap is a form of a lipid. Washing hands with soap traps the virus in tiny little soap bubble called micelles. Micelles are amphipathic, which means they like lipids but also water. When you rinse the soap from your hands with clean water, the micelles get carried away by the way taking the virus with it.

Can someone who’s infected spread the virus if they don’t have symptoms?

Unfortunately, yes. Viruses are pretty tricky. Before the host even begins to show symptoms, the virus has already been busy making lots of copies inside the host’s cells. Once you have a high enough load to show symptoms, you have already been shedding the virus through those early coughs and sneezes. In medical terms, this is called viral shedding which means you are shedding viral particles that can be transferred to a new host.

How does social distancing work?

Social distancing is a non-pharmaceutical intervention to prevent the spread of disease. The virus needs people close together to spread, so social distancing is an intervention that creates space between potential hosts. Think about making a domino train, if the dominoes get spread too far apart the train ends. Social distancing means you have to stay away from everyone that does not live in your residence, so no visitors. That can be a tough “non-pharmaceutical” pill to swallow. Trying to minimize trips to the grocery will help protect both you and those still working. Consider using things like click-list at Kroger (which is free during this crisis), or a shopping service like Shipt. Target and Wal-Mart also have drive-up options to keep people safe.

Can you get it from packaging or mail?

The risk appears to be low. News headlines have been citing a study published in the New England Journal of Medicine (here) which demonstrated that no viable virus particles were measured after 24 hours on cardboard, and 72 hours on plastic  Before you panic about that box, the virus can be detected on some surfaces for up to a day, but the reality is that the viable virus levels drop off quickly. Research shows that the virus’s half-life on plastic is 6.8 hours, meaning in just under 7 hours the number of virus particles that can make you sick is reduced by half. If you can let your boxes sit for a few hours before you open them, it is very unlikely you would get sick. If you do need to open the box and you’re concerned, open the box and wash your hands before grabbing your Amazon goodies. Dispose of the box, clean your counter, and wash your hands again before touching your new items.

Can I get sick from take-out?

Unlikely, but the risk is from the containers not the food. There is currently no evidence that COVID-19 is foodborne-driven. Steps to take to be safe: after setting down your take out on the counter, open the container, then wash your hands. Remove the food to a clean plate, dispose of the packaging, clean your counter and wash your hands. You should also be sure not to touch your face while eating. This could considerably eliminate the concern.

Who should wear a face mask?

This recommendation seems to be changing. The original guideline was only medical personal and those who were confirmed ill needed to wear a face mask. Later recommendations are suggesting that wearing masks can help prevent new infections. The virus is transmitted through airborne droplets. While coughing and sneezing into your arm prevent some of the droplets from touching nearby people, a mask can prevent those droplets from getting into your airways. The general population does need to be conscious that medical professionals are in desperate need of PPE (personal protective equipment), so we as a society need to make sure those individuals are cared for before keeping a mask for ourselves. If you do decide to wear a mask, be sure to keep your hands away from your face and resist touching the mask which is theoretically coated in the virus. When you remove the mask, be sure to wash your hands thoroughly.

How is it treated?

There are currently no treatments. Scientists are working on a vaccine and anti-virals to combat the virus, but those will take time. The best treatment is prevention — trying to avoid the virus altogether.

I’m young. I’m not supposed to get sick right?

The virus can affect all ages, and while hospitalization rates are higher for older individuals if you have any pre-existing health concerns, even mild asthma, you could be at greater risk for a more severe case.

How long until we can get back to normal?

That depends on society! The better job we do as a society to slow the spread by practicing social distancing the faster we can get back to normal.

What if I am experiencing symptoms?

Assume you have the virus, and try to stay home. Even if you receive the COVID-19 test and it turns up negative, data suggests that current coronavirus tests may have a particularly high rate of missing infections (up to 30% or higher). The best practice is to assume that you are infected and try to prevent the spread by staying home.

Where can I get more information?

The Center for Disease Control and the TN Health Department are updating information regarding the spread of the virus. If you want to learn more about the science of the disease, feel free to contact Dr. Phillips at

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