Understanding a New Virus

COVID-19 is caused by a coronavirus. This family of viruses is responsible for diseases ranging from the common cold to more serious respiratory illnesses, including two diseases you may have heard of called SARS and MERS. Coronaviruses are zoonotic, which means they originate in animals. It’s actually not uncommon for diseases to spread from animals to humans. In fact, several viruses that cause the flu came from pigs and birds. People can catch these viruses if they have direct contact with or consume an infected animal. The virus can then mutate, or change, to spread from person to person.

The first cases of COVID-19 seem to have originated in a live animal market in Wuhan. Since the virus’s discovery in humans late last year, researchers have been studying its genome. Results indicate that the virus’s hereditary material is similar to coronaviruses that came from bats. Interestingly, while these flying mammals might carry the disease, they don’t show signs of illness. “Bats don’t get sick like we do, so they can coexist with many different viruses,” says Williamson.

COVID-19 is caused by a coronavirus. This family of viruses causes many diseases. They include the common cold and more serious respiratory illnesses. You may have heard of two of them, called SARS and MERS. Coronaviruses are zoonotic, meaning they start in animals. It’s not uncommon for diseases to spread from animals to humans. In fact, several flu viruses came from pigs and birds. People might eat or have direct contact with an infected animal. Then they can catch these viruses. After that, the virus can mutate, or change, to spread from person to person.

The first cases of COVID-19 seem to have started in a live animal market in Wuhan. The virus was discovered in humans late last year. Since then, researchers have been studying its genome. Results show that the virus’s hereditary material is like that of coronaviruses from bats. Even though these flying mammals might carry the disease, they don’t show signs of illness. “Bats don’t get sick like we do, so they can coexist with many different viruses,” says Williamson.

To figure out how a virus like the one that causes COVID-19 spreads, public health scientists called epidemiologists study patterns of infection. For instance, when a patient is diagnosed with COVID-19, an epidemiologist will ask who the patient was in contact with in the 14 days prior to symptoms appearing. This process, called contact tracing, allows doctors to track down others who might be infected.

Early identification of people who’ve contracted the virus is important. If a person knows they have the virus, they can isolate themselves at home away from others. That can prevent new COVID-19 cases and eventually halt the virus’s spread.

Those infected with COVID-19 can be contagious for up to two weeks before showing signs of being ill. That’s why the Centers for Disease Control and Prevention recommended social distancing, where everyone—sick or not— avoids close contact with others. Many state and local governments also advised people to stay home from work, closed schools and businesses, and asked people to avoid large gatherings. Some hard-hit areas took additional steps like sanitizing public spaces, including subways, trains, and buses.

Public health scientists called epidemiologists try to learn how a virus like the one behind COVID-19 spreads. So they study patterns of infection. For example, when a patient is diagnosed with COVID-19, an epidemiologist asks a question. Whom was the patient around in the 14 days before symptoms appeared? This process is called contact tracing. It allows doctors to find others who might be infected.

If people have contracted the virus, it’s important to find out early. If they know they have it, they can isolate themselves at home away from others. That can prevent new COVID-19 cases. Over time, this can stop the virus’s spread.

People can be infected with the new coronavirus and show no signs for up to two weeks. But they can still be contagious. That’s why the Centers for Disease Control and Prevention recommended social distancing. The organization asked everyone, sick or not, to avoid close contact with others. Many state and local governments told people to stay home from work. They also closed schools and businesses and asked people to avoid large gatherings. Some hard-hit areas took even more steps. They disinfected public spaces, including subways, trains, and buses.

Scientists are working on a vaccine to prevent people from contracting COVID-19. A vaccine is a preventive measure that trains people’s immune systems to recognize a specific virus. If a vaccinated person is then exposed to the same virus later on, their body would be able to fight off the infection. But it will likely take at least a year until a COVID-19 vaccine is deemed safe and ready for the public, says Williamson. And because of how fast viruses mutate, scientists might need to develop new vaccines for COVID-19 each year, as they do for flu vaccines.

In the meantime, scientists are also searching for antivirals that could help treat patients with COVID-19. These medications inhibit viruses’ ability to function so they can no longer infect cells.

Scientists are working on a vaccine. It would prevent people from contracting COVID-19. A vaccine prevents infection by training people’s immune systems to recognize a certain virus. Later, vaccinated people might come across the same virus. But their bodies could fight off the infection. A COVID-19 vaccine must be considered safe and ready for the public. But that will likely take at least a year, says Williamson. And because viruses mutate so fast, scientists might need to develop new vaccines for COVID-19 each year. That’s what they do for flu vaccines.

At the same time, scientists are searching for antivirals to help treat patients with COVID-19. These medications keep viruses from functioning normally. Then they can’t infect more cells.

Since there’s currently no vaccine or medication to treat COVID-19, the best defense against the virus is everyday preventive behaviors. Along with social distancing, it’s important to wash your hands more frequently than usual.

Each of the virus particles that cause COVID-19 are surrounded by an envelope, or outer layer, made up of fats. Soap breaks apart this membrane, destroying the virus. That’s why thorough handwashing is one of the best ways to halt the virus in its tracks. It doesn’t matter if you wash your hands in warm or cold water, as long as you lather them up well and scrub all over for at least 20 seconds (see Healthy Handwashing). That’s about the amount of time it would take to sing “Happy Birthday” twice.

For now, it’s hard to know if the virus will disappear once the outbreak ends or whether it will reappear each year, in a way that’s similar to the seasonal flu, says Williamson. Even though that may sound scary, experts say it’s important to stay calm and do what’s necessary to protect one another.

Right now, there’s no vaccine for COVID-19 or medication to treat it. So the best defense against the virus is everyday preventive actions. Social distancing is important. So is washing your hands more often than usual.

An envelope, or outer layer, surrounds each of the virus particles that cause COVID-19. This membrane is made up of fats. Soap breaks it apart and destroys the virus. That’s why good handwashing is one of the best ways to stop the virus. It doesn’t matter if you wash your hands in warm or cold water. Just lather them up well and scrub all over for at least 20 seconds (see Healthy Handwashing). That’s about how long it would take to sing “Happy Birthday” twice.

Will the virus disappear when the outbreak ends? Or will it come back each year, like the seasonal flu? For now, it’s hard to know, says Williamson. That may sound scary. But experts say it’s important to stay calm and do what’s needed to protect one another.