Harvard Medical School: COVID-19 Questions & Answers
The rapid spread of the coronavirus that causes COVID-19 has sparked alarm worldwide. The World Health Organization (WHO) has declared a global health emergency, and many countries are grappling with a rise in confirmed cases. In the US, the Centers for Disease Control and Prevention (CDC) is advising people to be prepared for disruptions to daily life that will be necessary if the coronavirus spreads within communities.
Below, we’re responding to a number of questions about COVID-19 raised by Harvard Health Blog readers. We hope to add further questions and update answers as reliable information becomes available.
Does the coronavirus spread person-to-person?
Yes, the virus can spread from one person to another, most likely through droplets of saliva or mucus carried in the air for up to six feet or so when an infected person coughs or sneezes. Viral particles may be breathed in, land on surfaces that people touch, or be transferred when shaking hands or sharing a drink with someone who has the virus.
Often it’s obvious if a person is ill, but there are cases where people who do not feel sick have the virus and can spread it.
Basic steps for avoiding flu and other infections — including steps for handwashing shown in this video and avoiding touching your mouth, nose, and eyes — are likely to help stop the spread of this virus. The CDC has a helpful list of preventive steps.
Quarantines and travel restrictions now in place in many counties, including the US, are also intended to help break the chain of transmission. Public health authorities like the CDC may recommend other approaches for people who may have been exposed to the virus, including isolation at home and symptom monitoring for a period of time (usually 14 days), depending on level of risk for exposure. The CDC has guidelines for people who have the virus to help with recovery and prevent others from getting sick.
What is the incubation period for the coronavirus?
An incubation period is the time between being exposed to a germ and having symptoms of the illness. Current estimates suggest that symptoms of COVID-19 usually appear around five days on average, but the incubation period may be as short as two days to as long as 14 days.
What are the symptoms of the new coronavirus?
Fever, dry cough, and trouble breathing are the common symptoms of COVID-19. There have been some reports of gastrointestinal symptoms (nausea, vomiting, or diarrhea) before respiratory symptoms occur, but this is largely a respiratory virus.
Those who have the virus may have no obvious symptoms (be asymptomatic) or symptoms ranging from mild to severe. In some cases, the virus can cause pneumonia and potentially be life-threatening.
Most people who get sick will recover from COVID-19. Recovery time varies and, for people who are not severely ill, may be similar to the aftermath of a flulike illness. People with mild symptoms may recover within a few days. People who have pneumonia may take longer to recover (days to weeks). In cases of severe, life-threatening illness, it may take months for a person to recover, or the person may die.
Can people who are asymptomatic spread coronavirus?
A person who is asymptomatic may be shedding the virus and could make others ill. How often asymptomatic transmission is occurring is unclear.
Can the coronavirus live on soft surfaces like fabric or carpet? What about hard surfaces?
How long the new coronavirus can live on a soft surface — and more importantly, how easy or hard it is to spread this way — isn’t clear yet. So far, available evidence suggests it can be transmitted less easily from soft surfaces than frequently-touched hard surfaces, such as a doorknob or elevator button.
According to the WHO, coronaviruses may survive on surfaces for just a few hours or several days, although many factors will influence this, including surface material and weather.
That’s why personal preventive steps like frequently washing hands with soap and water or an alcohol-based hand sanitizer, and wiping down often-touched surfaces with disinfectants or a household cleaning spray, are a good idea.
Should I wear a face mask to protect against coronavirus? Should my children?
Follow public health recommendations where you live. Currently, face masks are not recommended for the general public in the US. The risk of catching the virus in the US is low overall, but will depend on community transmission, which is higher in some regions than in others. Even though there are confirmed cases of COVID-19 in the US, most people are more likely to catch and spread influenza (the flu). (So far this season, there have been nearly 30 million cases of flu and 17,000 deaths.)
Some health facilities require people to wear a mask under certain circumstances, such as if they have traveled from areas where coronavirus is spreading, or have been in contact with people who did or with people who have confirmed coronavirus.
If you have respiratory symptoms like coughing or sneezing, experts recommend wearing a mask to protect others. This may help contain droplets containing any type of virus, including the flu, and protect close contacts (anyone within three to six feet of the infected person).
The CDC offers more information about masks. The WHO offers videos and illustrations on when and how to use a mask.
Should someone who is immunocompromised wear a mask?
If you are immunocompromised because of an illness or treatment, talk to your doctor about whether wearing a mask is helpful for you in some situations. Advice could vary depending on your medical history and where you live. Many people will not need to wear a mask, but if your healthcare provider recommends wearing one in public areas because you have a particularly vulnerable immune system or for other reasons, follow that advice.
Should I accept packages from China?
There is no reason to suspect that packages from China harbor COVID-19. Remember, this is a respiratory virus similar to the flu. We don’t stop receiving packages from China during their flu season. We should follow that same logic for this novel pathogen.
Can I catch the coronavirus by eating food prepared by others?
We are still learning about transmission of COVID-19. It’s not clear if this is possible, but if so it would be more likely to be the exception than the rule. That said, COVID-19 and other coronaviruses have been detected in the stool of certain patients, so we currently cannot rule out the possibility of occasional transmission from infected food handlers. The virus would likely be killed by cooking the food.
Should I travel on a plane with my children?
Keep abreast of travel advisories from regulatory agencies and understand that this is a rapidly changing situation. The CDC has several levels of travel restrictions depending on risk in various countries and communities.
Of course, if anyone has a fever and respiratory symptoms, that person should not fly if at all possible. Anyone who has a fever and respiratory symptoms and flies anyway should wear a mask on an airplane.
Is there a vaccine available for coronavirus?
No vaccine is available, although scientists are working on vaccines. In 2003, scientists tried to develop a vaccine to prevent SARS but the epidemic ended before the vaccine could enter clinical trials.
Is there a treatment available for coronavirus?
Currently there is no specific antiviral treatment for this new coronavirus. Treatment is therefore supportive, which means giving fluids, medicine to reduce fever, and, in severe cases, supplemental oxygen. People who become critically ill from COVID-19 may need a respirator to help them breathe. Bacterial infection can complicate this viral infection. Patients may require antibiotics in cases of bacterial pneumonia as well as COVID-19.
Antiviral treatments used for HIV and other compounds are being investigated.
There’s no evidence that supplements, such as vitamin C, or probiotics will help speed recovery.
How is this new coronavirus confirmed?
A specialized test must be done to confirm that a person has COVID-19. Most testing in the United States has been performed at the CDC. However, testing will become more available throughout the country in the coming weeks.
How deadly is this coronavirus?
We don’t yet know. However, signs suggest that many people may have had mild cases of the virus and recovered without special treatment.
The original information from China likely overestimated the risk of death from the virus. Right now it appears that the risk of very serious illness and death is less than it was for SARS and MERS. In terms of total deaths in the United States, influenza overwhelmingly causes more deaths today than COVID-19.
What should people do if they think they have coronavirus or their child does? Go to an urgent care clinic? Go to the ER?
If you have a health care provider or pediatrician, call them first for advice. In most parts of the US, it’s far more likely to be the flu or another viral illness.
If you do not have a doctor and you are concerned that you or your child may have coronavirus, contact your local board of health. They can direct you to the best place for evaluation and treatment in your area.
Only people with symptoms of severe respiratory illness should seek medical care in the ER. Severe symptoms are rapid heart rate, low blood pressure, high or very low temperatures, confusion, trouble breathing, severe dehydration. Call ahead to tell the ER that you are coming so they can be prepared for your arrival.
Can people who recover from the coronavirus still be carriers and therefore spread it?
People who get COVID-19 need to work with providers and public health authorities to determine when they are no longer contagious.
- Harvard Health Publishing’s Coronavirus Resource Center
- WHO coronavirus website and answers to frequently asked questions
- WHO coronavirus mythbusters page
- CDC coronavirus website and answers to frequently asked questions
Also, read our earlier blog posts on coronavirus:
- The new coronavirus: What we do — and don’t — know
- Be careful where you get your news about coronavirus
- Coronavirus: What parents should know and do