Your Questions on Coronavirus, Answered

CR consulted with scientists and doctors to address reader questions about COVID-19

As the coronavirus spreads throughout the country and the world, so does misinformation about the pandemic. That's why Consumer Reports consulted with scientists and doctors to answer your questions and debunk myths that are circulating about COVID-19, the disease caused by the virus.

Here, we've addressed your most pressing concerns about cleaning, health, and safe handling to give you factual, easy-to-understand information that will help you protect yourself, your family, and your community.

Note that this article is being updated, as needed, as information about COVID-19 evolves.

No. Antibacterial soaps target bacteria, and coronavirus is a virus. So an antibacterial soap is unnecessary.

In fact, the Centers for Disease Control and Prevention doesn't recommend that consumers use soaps with antibacterial ingredients even to reduce the risk of bacterial infections, noting that research shows antibacterial soaps offer no added benefit for consumers compared with plain soap.

Rubbing your hands together with plain soap and water is extremely effective at removing germs. "The main role of soap is to remove what's stuck on your hands, whether that's dirt, a bacterial cell, or a virus particle," says Don Schaffner, Ph.D., a microbiologist and distinguished professor at Rutgers University.

Soap is not designed to kill germs on contact, but rather to wash germs away. "The surfactants in soap lift up and break apart dirt and microbes from your skin, and the friction of rubbing your hands together helps remove the particles so they get washed down the drain," Schaffner says.

The most important thing to know about coronavirus and hand-washing is that you should wash your hands thoroughly with soap and water for 20 seconds after you touch public or other surfaces that might be contaminated with the virus. And remember to wash your hands after you use the bathroom, before you eat, and after coughing, sneezing, or wiping your nose.

Yes, and it's soap. "Regular soap is incredibly natural," Schaffner says. Its main ingredients are fats or oils (like shea butter and coconut oil) and lye (sodium hydroxide), and the resulting product is gentle on the skin.

Other "natural" cleaners being touted lately, such as tea tree oil and vinegar, have not been shown to work against COVID-19.

Though distilled white vinegar is a non-toxic cleanser, in some instances it isn't wise to use or even effective. And when it comes to the new coronavirus, "vinegar doesn't work," says Mary E. Schmidt, M.D., an infectious disease specialist and associate professor of clinical medicine at Virginia Commonwealth University in Richmond.

As for tea tree oil, though it does have antibacterial properties, "there are no studies showing tea tree oil works for coronavirus," Schmidt says.

Yes. The ingredients in disinfectant wipes inactivate viral microbes so that they are no longer infectious. "It's a best practice to wipe down your grocery cart handle with a disinfectant product when you enter the store," Schaffner says.

The Environmental Protection Agency also lists disinfectant wipes (which may contain quaternary ammonium, sodium hypochlorite, hydrogen peroxide, ethanol, or isopropanol) as effective in protecting against SARS-CoV-2 (the official term for the new coronavirus). For best results, vigorously wipe down the cart handle and let the surface dry completely before touching it again.

"We know that coronavirus can stick around on surfaces, so wipe down touch-points in the laundry room when you enter," says Sean O’Leary, M.D., associate professor of pediatrics and pediatric infectious diseases at the University of Colorado Denver Anschutz Medical Campus in Aurora. For instance, use a disinfectant wipe to clean handles, knobs, and switches so that you don't pick up any viral microbes that may be on those surfaces.

While doing laundry, avoid touching your face, and consider wearing disposable or washable gloves. Ideally, bring your own laundry cart so that you don't need to use a communal one. Then wash your clothes and linens with your detergent of choice and use the warmest water setting appropriate for your fabrics. Bleach is not necessary, but it does further inactivate germs. (For more, follow these tips for washing clothes to prevent the spread of COVID-19.) Also, if you can, dry your clothes in the dryer because the heat may also help inactivate any viral microbes.

Most important is to remember that the best way to reduce your potential exposure to coronavirus in any shared space is to stay at least 6 feet away from the other people there. So don't hang out in the laundry room while your clothes are in the washing machine or the dryer. Instead, leave and go wash your hands.

Yes. Though it's safest to use a store-bought cleaner, the Centers for Disease Control and Prevention recommends a diluted bleach solution (⅓ cup bleach per 1 gallon of water or 4 teaspoons bleach per 1 quart of water) for virus disinfection.

If you don't have bleach, you could use isopropyl alcohol or hydrogen peroxide to disinfect certain surfaces. But do not mix different active ingredients together because doing so can create poisonous gases and cause serious burns.

"An important general rule is that you shouldn't immediately wipe a disinfecting solution off as soon as you’ve applied it to a surface," Schaffner says. "Let it sit there long enough to kill the viruses first." Read the product's directions and let it dry completely.

If you can't find your favorite brand of cleaner right now, know that there are many store-bought products that work to inactivate viruses. You could look for options on the Environmental Protection Agency's website, which has a list of disinfectants that meet the agency's criteria for use against the new coronavirus. And see our report on household cleaners that destroy the coronavirus.

One thing you should not make at home: hand sanitizer. "If made incorrectly, hand sanitizer can be ineffective, and there have been reports of skin burns from homemade hand sanitizer," according to the Food and Drug Administration. "The agency lacks verifiable information on the methods being used to prepare hand sanitizer at home and whether they are safe for use on human skin."

Most likely. UV light can inactivate bacteria and viruses under certain conditions, and UV radiation has been used to disinfect various things, such as drinking water, air, and titanium implants, Schmidt says. But to date she has "found no quality scientific studies showing that sunlight actually kills coronavirus," and there are no guidelines on how it might be used on various surfaces or in different settings and temperatures.

What's more, UV light from the sun (UVA and UVB) is extremely damaging to skin, so you wouldn't want to expose yourself to UV rays in the hopes of inactivating coronavirus. If you're wondering whether placing an inanimate object, like your phone, outdoors to bask in the sun's rays will inactivate coronavirus microbes, "it's theoretically possible but not recommended," Schmidt says.

What about UV radiation devices marketed to disinfect items? These are often lamps or wands that use a different type of UV light, called UVC, which is normally filtered out by the ozone in the atmosphere. Some research shows that UVC light may inactivate another type of coronavirus under carefully controlled conditions. "It wouldn't surprise me if those devices work to inactivate the new coronavirus but there are no studies on that yet, and I don't know that the gadgets are any more effective than using a disinfectant like isopropyl alcohol or ethyl alcohol," Schaffner says. UVC light can also be extremely harmful to your eyes and skin if not used properly. For consumers, Schaffner says, "there are more reliable and less expensive ways to disinfect surfaces."

Yes, it's possible.

The current test for COVID-19 is designed to detect the new coronavirus genome in samples that are taken from the back of the nose or throat.

While there is limited data at this point, false negatives with this test—when the test incorrectly says a person is not infected—are thought to occur about 30 percent of the time, according to Rochelle Walenksy, M.D., professor of medicine at Harvard Medical School and an infectious disease physician at Massachusetts General Hospital and Brigham and Women's Hospital. This estimate has changed over the past few weeks as an increasing number of people have been tested.

A false negative could happen if "you were very early in your infection at the time of your specimen collection," the CDC says. There are also other circumstances that could lead to a false negative, says Schmidt at Virginia Commonwealth University, including if the sample was not collected correctly; if the virus was at a later stage and all the virus particles in the back of the nose and throat were gone or bound to antibodies; if the sample was not handled or prepared correctly; or if the test was misread.

False positives—or when a test incorrectly says that you are infected—"are rarer," Schmidt says, "and would be caused by cross contamination or human error in data reporting."

Walensky notes that if the test shows a positive result, "we believe we can trust that."

Soon, blood tests will be available to check for antibodies to COVID-19. This test can't identify who has an active infection but would indicate whether you had been exposed to the virus and developed an immune response to it. These tests (called serological tests) typically have rates of false negatives and false positives between 5 and 20 percent, Schmidt says. They will be critical for helping public health experts determine the scale of the outbreak's spread.

Bottom line: At this point, if you are tested for the new coronavirus, follow your doctor's instructions.

Scientists don't have the answer yet. Research is underway to better understand immunity to the new coronavirus, and some early studies indicate immunity could develop and last for months to a year, Schmidt says.

But it's too early to offer any advice on this front. In the case of MERS-CoV, another type of coronavirus, the CDC found that infected patients were unlikely to be reinfected shortly after recovery, but it's unclear whether or not the same immune protection would happen in people with COVID-19.

Yes, it's possible to have more than one infection at a time, says Mobeen Rathore, M.D., chief of pediatric infectious diseases and immunology for Wolfson Children's Hospital in Jacksonville, Fla. Preliminary research done by scientists at Stanford University found that there may actually be higher rates of coinfection in people who tested positive for COVID-19 than initially reported. Of the small sample of patients with COVID-19 they studied, about 22 percent had another viral infection, such as influenza, enterovirus, or respiratory syncytial virus.

"We see coinfections with other viral infections, also, so this is not surprising," Rathore says.

No. Though an email chain was circulating that advised people to do this, "we don't have any evidence that this is true," says W. Graham Carlos, M.D., associate professor of clinical medicine at Indiana University School of Medicine.

It's unlikely. While early research shows that the new coronavirus can remain infectious on cardboard for up to 24 hours and on metal and plastic for up to 72 hours, the World Health Organization states that "the likelihood of an infected person contaminating commercial goods is low and the risk of catching the virus that causes COVID-19 from a package that has been moved, traveled, and exposed to different conditions and temperature is also low."

Similarly, the CDC states that "there is likely very low risk of spread from products or packaging that are shipped over a period of days or weeks at ambient temperatures."

The most likely mode of transmission for the new coronavirus is through respiratory droplets, for instance if an infected person were to cough or sneeze near you.

Yes, it's possible. While studies have not yet been done to determine how long COVID-19 can remain infectious on fabrics, it is likely that the virus can survive on clothes, sheets, and towels for hours or days, says Jaimie Meyer, M.D., an infectious disease specialist at Yale Medicine, in New Haven, Conn.

Though the virus is more transferable and infectious through sneeze or cough droplets, you could pick up viral microbes from someone's clothes, especially if they are wet. So if someone has a confirmed or suspected case of COVID-19, consider their clothes to be contaminated. Handle these clothes carefully when washing them, don't touch your face, and wash your hands thoroughly afterward.

The safest way to deliver supplies to your neighbors is to place the items on their front porch or outside their door, Schaffner says. Clean your hands thoroughly before touching the supplies, and if you happen to cough or sneeze in the vicinity of the items, turn your mouth into your bent elbow—away from the items.

Call or text your neighbor after you’ve left the bags outside the door so that you don't need to interact with each other directly. If you do want to say hello in person, stand at least 6 feet away from the door so that you don't exchange germs through any respiratory droplets in the air.

Editor's Note: This article, originally published on March 30, 2020, has been updated to include a revised estimate of the rate of false positives for the novel coronavirus test.

Rachel Rabkin Peachman

I'm a science journalist turned investigative reporter on CR's Special Projects team. My job is to shed light on issues affecting people's health, safety, and well-being. I've dug deep into problems such as dangerous doctors, deadly children's products, and contamination in our food supply. Got a tip? Follow me on Twitter (@RachelPeachman).