Coronavirus Disease 2019 (COVID-19)

Sometimes referred to as: Severe Acute Respiratory Syndrome Coronavirus 2

Interview between:

  • Jimmy Chen, MD

  • Nora Lansen, MD

COVID-19 is an infectious disease, caused by a new strain of coronavirus. The World Health Organization first declared COVID-19 a pandemic in March 2020, and within a year, over 125 million people worldwide have been infected.

Cases Per Year (US)

More than 30 million cases (as of March 2021).

General Frequency

At least 9% of the U.S. population, and 1.5% of the world population have been infected (as of March 2021).


While most people who have COVID-19 develop mild symptoms, some groups, such as older adults and people with certain underlying medical conditions, can develop more serious complications.



What are the symptoms of COVID?  

People with COVID-19 can experience a wide range of symptoms, from mild to severe. The most common of these include fever, dry cough, shortness of breath, and fatigue. After exposure, symptoms typically appear within five days but the process can sometimes take up to 14 days.

How does COVID spread?  

COVID-19 spreads mainly through respiratory droplets, which are released when an infected person coughs, sneezes, or talks to another individual nearby (or within six feet). 

Other less common forms of transmission include airborne—which occurs when droplets linger in the air for several minutes to hours after an infected person has left the area—and also the act of touching contaminated surfaces and then touching one’s mouth, nose, or eyes. Importantly, recent studies have shown that about 20% of infected people do not show any symptoms, but can still spread the virus to others.

If I have antibodies, am I immune? And can I pass COVID to others?

Having antibodies against COVID-19 does suggest some protection against reinfection, but at this time, we do not know exactly how much protection is provided or how long this immunity lasts. While there have been documented cases of reinfection, so far these remain rare. Also, with the increasing number of different COVID-19 variants circulating worldwide, we do not know if having antibodies against one strain will protect against another strain.

What do I need to know about the variants?

Part of the reason why the COVID-19 pandemic has been so difficult to control is because the virus constantly mutates and changes over time, thereby creating new variants. 

As of March 2021, there are at least five identified variants of concern in the US, including one initially identified in the UK (called B.1.1.7), one from South Africa (B.1.351), one from Brazil (P.1), and two from California (B.1.427 and B.1.429). These new variants of concern have been shown to be more contagious, cause more severe disease including hospitalizations and deaths, and possibly evade current treatments or vaccines.







Connect with our physicians

Jimmy Chen, MD and Nora Lansen, MD are both members of the Galileo Clinical Team. Connect with one of our physicians about Coronavirus Disease 2019 (COVID-19) or any of the many other conditions we treat.

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