There’s still much to learn about the disease that has killed thousands of people and is changing life as we know it during this pandemic. But we do know some important basics about COVID-19 and the novel coronavirus—SARS-CoV-2—that causes it.
Coronaviruses are a large family, but only seven of its members infect humans. Four types cause minor illnesses like the common cold, while other coronaviruses have triggered far more devastating impacts such as SARS, MERS, and now COVID-19. Coronaviruses can be zoonotic, meaning they jump from animals to humans. Like its relatives, COVID-19 is primarily a respiratory disease that starts in the lungs, causing pneumonia-like symptoms, but can also cast a storm across the entire body.
The virus primarily spreads through small respiratory droplets.
Like other respiratory diseases, COVID-19 spreads through small droplets—saliva or mucus—that an infected person expels when they cough, sneeze, or talk. These droplets can travel three to six feet and remain infectious for anywhere from four to 48 hours, depending on the surface. (The virus may also spread via accidental consumption of fecal matter or aerosols, tiny particles that are mostly a concern in clinical settings.)
On surfaces, it lives longer.
You can protect yourself from catching the virus by staying six feet away from others and washing your hands with soap and water for more than 20 seconds. Disinfectants that are at least 60 percent alcohol by volume can also kill the virus on plastic and stainless steel surfaces.
Coronaviruses get their name from their spiky structure.
Like other coronaviruses, SARS-CoV-2 is spherical with spike proteins that look a bit like a corona, or crown.
Those spikes help the virus latch onto cells where it can invade.
Once a virus enters the human body through the eyes, mouth, or nose, it looks for cells with its favorite doorways—proteins called receptors. If the virus finds a compatible receptor, it can invade and start replicating itself. For SARS-CoV-2, that receptor is found in lung cells and the gut.
Age seems to factor into the severity of the disease.
Currently, children with COVID-19 may be less likely to require intensive care and also have lower fatality rates than adults. The difference in severity is not yet fully understood.
There isn’t a single diagnostic symptom, but some are more common.
People with chronic conditions have a higher mortality rate.
COVID-19 poses a particularly serious threat to people with underlying conditions such as cardiovascular disease, diabetes, chronic lung disease, high blood pressure, and cancer.
Testing is done to diagnose the presence of the virus.
Swab samples taken from the nose or mouth are tested for the virus’s genetic material. Researchers are also developing protocols for tests using blood samples.
It could take at least one year before a vaccine is ready for public use.
To develop immunity, vaccines may contain killed or weakened virus, viral proteins, or viral genetic material. The best strategy to use against SARS-CoV-2 is yet to be determined.