Johns Hopkins experts are learning more about the coronavirus. Here’s what they want you to know.

As much of Maryland and the United States hunker down at home to help stop spread of the coronavirus, scientists are making progress in understanding how the virus is transmitted, how it affects humans and, most importantly, how it can be stopped.

Experts at the Johns Hopkins Bloomberg School of Public Health offered some updates and things people can do now. This Q&A is adapted from a webcast moderated by Dr. Joshua Sharfstein, vice dean for public health practice and community engagement, and including Andy Pekosz, professor of molecular microbiology and immunology, and Caitlin Rivers, senior scholar in the Center for Health Security.

How infectious is this coronavirus?

It’s pretty good at spreading from person to person, better than some other coronaviruses including MERS and SARS. So there are more infections, but unlike those others it mostly causes mild illness. Those with serious symptoms of the disease named COVID-19, such as trouble breathing and fever, are more likely to seek care, though those with mild disease are still infectious and “driving the transmission train,” as they go about their day, Pekosz said.

Scientists are using cell cultures in the lab to mimic the upper respiratory track of humans so they can see why the virus spreads so efficiently and what may stop it.

How is the virus transmitted from person to person?

The culprits are the rather large droplets that people cough or sneeze through the air to people or common surfaces. This is why it’s important to cover your mouth when you cough or sneeze and avoid touching your face and stay three to six feet away from others. Fine droplets that float around the air don’t seem to cause as much trouble.

How long can the virus live on surfaces and how can you kill it?

It can live on surfaces, such as railings and tables and phones for a few hours to up to 24 hours. But the virus is sensitive to antimicrobial cleaners. Use cleaners that are marked antimicrobial or dilute bleach with water at a 1 to 10 ratio and wipe. If you don’t have those, use rubbing alcohol from the medicine cabinet. You can use right from the bottle if it’s 70% or dilute it a bit if it’s 90% to make it go a little farther.

Will we get a respite when it gets warm?

The short answer is no one knows. Other viruses, such as flu viruses, are way less efficient at spreading in the summer. But since this is a new virus and no one has immunity, it still could infect people. That’s what happened during the 2009 H1N1 flu outbreak.

[ Coronavirus in Maryland: full coverage ]

“We have to prepare for dealing with this during the summer,” he said.

Can we use antibodies from those who have recovered for treatment?

It’s being studied at Hopkins and elsewhere. Studies in China suggest this could work, and there is a history of using antibodies from survivors of other infectious diseases.

Is a vaccine coming?

The first vaccine trial in humans have begun, and a trial for a second vaccine will begin soon. These are early stage trials, however, only testing the vaccine’s safety and not its effectiveness. This is amazing speed, since the virus was only genetically mapped in the past two months, but that doesn’t mean people will be inoculated widely any time soon. The vaccines will need to be tested to see if they work against the virus in later-stage trials. An effective vaccine is still likely 12 to 18 months away.

“This is not a short-term solution,” Pekosz said.

Are people becoming aware and taking proper steps to control spread in the meantime?

Testing is expanding and awareness of procedures to control spread appear to be taking hold. But the number of cases is likely to continue going up. Any tactics mandated now won’t show up in data for seven to 10 days because the incubation period, the time between infection and symptoms, is about five days and then people have to realize they are sick and call their doctor.

“Maintain vigilance, however, because it does help,” Rivers said.

What is “social distancing”?

This is putting physical space between people so the virus has a harder time transmitting through those droplets. Spread control also means a lot of hand washing — particularly after returning from outside or before eating — avoiding high touch surfaces, such as grocery carts that are not wiped down, and staying home, especially when sick.

Closing bars, restaurants and schools and canceling large events can have big effects because that reduces crowds of people.

Are some countries doing a better job at this?

Countries do seem to be having different experiences. France and Italy had a lot of sick people while some Asian countries have not. This could be because those in some Asian countries were heavily impacted by other coronavirus outbreaks such as SARS and have learned lessons on social distancing. Some of those countries have had lower rates of other infections such as pink eye, which shows mitigation measures work in general.

What does it mean to “flatten the curve”?

The idea is that if transmission slows, it leads to fewer new cases at one time. For example, if 100 people get sick, they get sick over 10 weeks, instead of in one week. This helps the health care system manage everyone’s illnesses.

[ Do you have a fever, cough and suspect coronavirus? Here’s what to do. ]

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We are closer to the beginning of the curve at this time.

If you are young and healthy and not at particular risk do you still need to practice social distancing?

It’s true that young healthy people have lower risk of the illness, but they are a “bridge” to older and sicker people, Rivers said. Disease can spread only if there are people to spread it to. Sometimes those vulnerable people have to leave home for groceries or doctor visits and they could come into contact with others who are infected and may not know or aren’t being vigilant.

Think about it as infecting your grandparents.

What should you do about your routine doctor’s visit and what should the doctor’s office be doing?

If you don’t need to go now, don’t go. If you do go, and you’re healthy, a mask won’t help you. The masks are for those who are sick. And if you are sick, call ahead to let the office know so they can get you directly to an isolated room so you don’t infect others.

Offices and hospitals should consider canceling elective procedures and visits. They should wipe their surfaces regularly and have sanitizer at the ready.

Is it okay to go outside?

It’s more than okay. It’s a good idea. Just keep your distance from others. Walking, hiking and biking are good. Contact sports are a no-no.

Exercise is physically and mentally important, especially in stressful times. If you know someone who can’t go outside, like an older person, call them regularly. Social distancing only applies to physical space, not all human connections.