COVID-19 is the name of the disease caused by the most recently discovered coronavirus (SARS-CoV-2). An outbreak began in Wuhan, China, in December 2019 and has now become a global pandemic due to its high infectivity.

What are Coronaviruses?

Coronaviruses are a large family of viruses known to cause illness in animals and humans. Some cause mild respiratory illness such as the common cold but some are known to cause more severe disease such as Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS).


COVID-19 is the disease caused by the SARS-CoV-2 virus which is the most recently discovered coronavirus and is genetically similar to SARS. COVID-19's symptoms typically are more mild than those of SARS but tends to be more infectious.

Why is COVID-19 Concerning?

COVID-19 infections are usually mild, especially in children and young adults with no medical complications. However, we know based on outbreak data from countries like China and Italy that elderly individuals (>65 years old) are much more likely to require hospitalization and intensive care.


The virus that causes COVID-19 is very infective and can be transferred easily between person to person even when only mild symptoms are present. If enough people are affected and require advanced care the healthcare system can quickly become overwhelmed.

For more information, please click the image below to access a virology course which integrates teaching with the current COVID-19 situation. The course is taught by Dr. Vincent Racaniello from Columbia University's College or Physicians and Surgeons.