Ten pressing questions about coronavirus, answered by experts

A health personnel tested a woman's temperature in the triage area at the Molinette hospital as they try to prevent further coronavirus cases in Turin, Italy.Stefano Guidi/Gett

With worries about the coronavirus growing globally, so too are many questions about the new health threat. Here are answers to some key questions from veteran health reporter Felice J. Freyer.

What does it feel like to have the new coronavirus?

The illness, now known as Covid-19, feels similar to the flu. The main symptoms are fever, cough, and shortness of breath. Although this is a new virus, so far it appears that the illness is mild in 80 percent of those who get it. An unknown number of people get infected but have no symptoms at all.

What are the symptoms of coronavirus, and how is it treated?

The US Centers for Disease Control says little is known about the virus, but it still has some tentative answers.

That doesn’t sound so bad. What’s the big deal?

For starters, 20 percent do get severely ill and can develop pneumonia. Some even need intensive care and mechanical ventilation. Covid-19 sufferers could overwhelm hospitals if the epidemic spreads in this country.

Children don’t seem to be affected. But elderly people and people with chronic illnesses are at high risk. So even if you survive a Covid-19 outbreak, someone you know may not.

What is the death rate?

A recent study of the Chinese outbreak put the death rate at 2.3 percent. That’s more than 20 times higher than the death rate from seasonal flu. It’s possible that number will change when it becomes clear how many people have been infected.

Another study of 1,099 Covid-19 patients who were hospitalized in China, published Friday, found that 1.4 percent of them died.

In what other ways is Covid-19 different from the flu?

It’s more contagious. Each person who gets sick with Covid-19 on average infects two or three other people. For the flu, it’s closer to one person.

How does Covid-19 spread?

Doctors believe that the primary mode of transmission is the same as for the flu or a cold: When an infected person coughs or sneezes, droplets bearing the virus spray into the air and then quickly fall to surfaces below. If you’re within 6 feet of a coughing and sneezing person, you could catch it. If you touch a surface with live virus still on it, and then touch your mouth, nose, or eyes, you can become infected. It’s not known how long the virus survives on surfaces.

But there are other possibilities, still under investigation. The virus that causes Covid-19 has been found in stool samples, so it’s possible it spreads through feces. And researchers have not ruled out the possibility that the virus can become airborne and able to travel through ventilation systems.

What is the treatment for Covid-19?

So far, there is none, although a new collaboration between Harvard Medical School and Chinese scientists is working on it.

The National Institutes of Health has begun testing an antiviral called remdesivir to see if it can treat Covid-19. But all these efforts take months.

Meanwhile, when people with Covid-19 go to the hospital, they get what is called “supportive care” — that is, doctors help them breathe and fight off infections until their own immune systems can defeat the virus.

Why is there no vaccine?

This virus is entirely new, and vaccine development is a long process. It also takes money, and pharmaceutical companies have little incentive to develop vaccines because they’re not profitable. Still, at the urging of the federal government, a few companies are at work on it. Moderna Therapeutics, based in Cambridge, recently submitted a candidate vaccine for early testing.

But testing takes time. To give a vaccine to a population of healthy people, researchers have to be confident that the risk of harm is exceedingly low. Vaccine candidates have to be tested in animals and then in people. That takes many months.

How can I avoid getting sick?

You may be tired of hearing it, but your best defense really is to wash your hands often when out in public. Bring along a little bottle of hand sanitizer for backup. Put a real emphasis on washing often. It really works. Also avoid touching your face. The virus gets into your body through your mouth, nose, and eyes.

Dr. Paul Biddinger, chief of emergency preparedness at Massachusetts General Hospital, said that studies during the outbreak of SARS, a similar coronavirus, found that hand-washing and avoiding touching the face decreased the risk of illness by 30 percent to 50 percent.

Also, try to stay away from sick people.

And if you’re sick, do your part — cough into your sleeve, stay home.

How worried should I be?

There is so much we still don’t know about this virus and how it will play out if it starts spreading more widely in the United States. Perhaps it will affect only certain regions or sicken few people. Perhaps it will roar across the country, filling hospital wards and morgues. Or maybe the result will be something in between.

For many people, the biggest difficulties may not be illness but the disruption of daily life as the result of such possible measures as school and business closings, event cancellations, supply chain disruptions, and travel restrictions.

Should you worry? Uncertainty is hard to cope with — but worrying can be unproductive. A better approach might be to plan, to think about what you might need to do if things get bad. Ask your employer what plans are in place if you can’t get to work. Can you work at home if need be? Do you have the equipment needed? Fill your prescription medications to ensure you will have some on hand if you need to stay home for a couple of weeks. If a child or elderly person depends on you, think of who can take care of them if you’re sick or quarantined.

King County in Washington state has posted a pandemic preparedness checklist that can help you think ahead.

Priyanka Dayal McCluskey of the Globe staff contributed to this report.