Like many others, you probably have questions about the novel coronavirus. And one of those questions may have to do with how the virus is able to spread.

First, some brief explanation about the coronavirus itself: The clinical name for this coronavirus is SARS-CoV-2. It stands for “severe acute respiratory syndrome coronavirus 2,” which means it’s a respiratory virus and is transmitted through respiratory droplets.

The infection caused by this virus is called COVID-19. So, if a person contracts the virus, the resulting disease is called COVID-19.

It originated from a family of other viruses that causes respiratory diseases like severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS).

Because this coronavirus is so new, it’s unfamiliar to our immune systems. And for nearly a year after the COVID-19 pandemic began, there wasn’t a vaccine to help protect you from this virus.

However, today there are three COVID-19 vaccines available in the United States:

Let’s take a closer look at how the novel coronavirus is transmitted from one person to another, and what you can do to protect yourself.

To curb COVID-19 transmission, the Centers for Disease Control and Prevention (CDC) recommends wearing a well-fitted face mask if you’re:

  • not fully vaccinated (this applies to anyone 2 years of age and older)
  • fully vaccinated and have a weakened immune system, whether from medication or an underlying health condition
  • fully vaccinated and are in a region with a high COVID-19 transmission or case rate

According to the CDC, you typically don’t need to wear a mask in outdoor areas, unless you’re in close contact with people who aren’t fully vaccinated or in a crowded outdoor space.

Person-to-person contact is considered the main method of coronavirus transmission, according to the CDC.

Imagine sitting next to someone with a coronavirus infection on the bus or in a meeting room. Suddenly, this person sneezes, coughs, or laughs out loud.

If they don’t cover their mouth and nose, they will release respiratory droplets into the air and on others. These droplets may contain the virus.

Or perhaps you meet someone who contracted the virus, and they touched their mouth or nose with their hand. When that person shakes your hand, they transfer some of the virus to your hand.

If you then touch your mouth or nose without washing your hands first, you may accidentally give that virus an entry point into your own body.

Or you might inhale some of those respiratory droplets that hang in the air — sometimes for hours — after a person with an infection has coughed, sneezed, laughed, or simply spoken. If you’re indoors, those fine droplets and particles can spread and accumulate.

One small study published early in the pandemic suggested that the virus may also be present in feces and could contaminate places like toilet bowls and bathroom sinks. But the researchers noted the possibility of this being a mode of transmission needs more research.

Pregnancy and breastfeeding

For a while, medical experts weren’t sure whether it was possible for a pregnant person to transmit SARS-CoV-2 in utero, through childbirth, or through their breast milk.

A review of studies published in early 2021 in the American Journal of Obstetrics and Gynecology, however, did find some instances in which a pregnant person transmitted a coronavirus infection to their baby in utero during the third trimester. This phenomenon is known as vertical transmission.

However, the CDC reassures that most babies born to mothers with COVID-19 do not have the disease when they’re born.

There are no known reports of a mother passing the virus to their baby through breast milk. It’s possible, however, for a breastfeeding mother to pass the virus to their baby through respiratory droplets.

The CDC currently recommends that mothers with a confirmed infection, as well as those who may have an infection, are temporarily separated from their newborns. This separation helps decrease the risk of transmission.

Pregnant people and new mothers should speak with their doctors about the benefits and risks of breastfeeding.

The CDC has some guidelines that might help if you’re breastfeeding or caring for a new baby while you have COVID-19. They include:

  • Wear a face mask when you’re within 6 feet of your infant or when expressing breast milk.
  • Wash your hands thoroughly before holding or breastfeeding your infant.
  • Wash your hands thoroughly before touching a bottle or breast pump.
  • Clean the breast pump each time it’s used.

You could also consider having someone who isn’t sick and is fully vaccinated against COVID-19 to use expressed breast milk to feed your infant.

Summary

Person-to-person contact seems to be the main method of transmission of the novel coronavirus.

Transmission typically occurs when:

  1. You breathe in respiratory droplets that contain the coronavirus.
  2. Respiratory droplets (from talking, coughing, sneezing, etc.) or small particles containing the virus land on your mouth, nose, or eyes.
  3. You touch your face with your hands that have virus particles on them, which gives the virus an entry point via your mouth, nose, or eyes.

According to the CDC, the Delta variant (also known as B.1.617.2), which was first detected in India, spreads more easily and causes more infections than earlier versions of SARS-CoV-2.

In fact, the Delta variant is believed to be twice as infectious as other versions of the novel coronavirus. Some experts suggest that mutations, such as changes to the virus’s spike protein, may make the altered virus (the variant) stick more tightly to our cells once the virus invades the body.

Although some breakthrough infections are normal in vaccinated people, COVID-19 vaccines are still the most effective method of preventing an infection with any of the coronavirus variants.

We know that the coronavirus spreads more easily indoors in poorly ventilated spaces.

According to the Environmental Protection Agency, respiratory droplets containing the virus can accumulate indoors and spread more easily than in outdoor spaces.

In fact, the particles can spread throughout an entire room and linger. The particles can remain airborne for hours after the person with a coronavirus infection leaves the room.

Yes. You can transmit the coronavirus even if you don’t know you have an infection.

Experts believe it’s possible that someone with a coronavirus infection could transmit it to others even if they don’t show any symptoms, or have such mild symptoms that they don’t really know they’re sick.

In fact, an analysis published in early 2021 suggested that asymptomatic transmission was responsible for more than half the COVID-19 cases in the eight studies from which the researchers pulled data.

Someone who has contracted the coronavirus can transmit it when they’re showing symptoms. But someone may be able to transmit the virus even before they start to show COVID-19 symptoms.

The symptoms of COVID-19 can take anywhere from 2 to 14 days to show up after exposure to the virus.

A 2021 study found that the coronavirus is most contagious in the 2 days before and 3 days after a person begins experiencing symptoms.

One May 2020 study involving 181 people with COVID-19 found a median coronavirus incubation period of about 5 days, with more than 97 percent of participants showing symptoms by 11.5 days after exposure to the virus.

Summary

According to the CDC, the novel coronavirus is most infectious when a person is showing COVID-19 symptoms. However, recent studies have shown that someone can still transmit the virus even if they haven’t yet developed COVID-19 symptoms.

If you’re fully vaccinated against COVID-19, you are far less likely to contract an infection than someone who is unvaccinated.

If you do contract a breakthrough infection and develop COVID-19, the disease tends to be mild in most vaccinated people. You’re less likely to transmit it to others, too.

However, according to the CDC, if you do contract a breakthrough infection of the Delta variant, it’s possible to transmit the infection to other people.

Think of all the frequently touched surfaces where germs can lurk: kitchen counters, bathroom counters, doorknobs, elevator buttons, the handle on the refrigerator, handrails on staircases. The list goes on and on.

Early in the pandemic, experts were uncertain how long the coronavirus could survive on those surfaces and whether that posed a threat.

However, in early 2021, the CDC acknowledged that while transmission from contaminated surfaces is possible, “the risk is generally considered to be low.”

But if you think a surface may be contaminated, especially if you know you’re likely to touch it and then touch your face, clean the surface thoroughly with a disinfectant. A diluted bleach solution or an EPA-approved disinfectant is likely the most effective cleaner for this purpose.

And if someone in your home is sick, frequently clean those surfaces. Remember to thoroughly wash your hands afterward.

Summary

Experts don’t know for sure how long the novel coronavirus can survive on surfaces. However, the risk of contamination from surfaces is thought to be low.

It can be difficult to avoid being exposed to the coronavirus, especially if you’re often surrounded by other people or work in a high-risk setting. But, according to the CDC, there are a number of things you can do to protect yourself:

  • Get vaccinated. COVID-19 vaccines are safe and effective. In the United States, they are widely available at no cost. You can visit Vaccines.gov to find a vaccination provider near you, or check with retail stores, pharmacies, and medical offices in your area.
  • Stand back. Try to stay clear of people who are coughing or sneezing. The CDC suggests staying at least 6 feet away from people who may be sick.
  • Wear a mask. Wearing a properly fitting mask indoors may help protect you if you come in contact with someone who has COVID-19.
  • Wash your hands frequently. Wash your hands thoroughly with soap and water for at least 20 seconds every time you’ve been around other people or touched common surfaces that could be contaminated.
  • Use alcohol-based hand sanitizer. If you don’t have access to soap and water, use a hand sanitizer that’s at least 60 percent alcohol.
  • Avoid touching your face. You can easily transmit the virus from unwashed hands to your mouth, nose, or eyes.
  • Stay home when possible. Staying away from large groups of people may help you avoid being exposed to the virus.
  • Get a booster. All adults in the United States can now get a COVID-19 vaccine booster. According to the CDC, you can get a booster 6 months after receiving your second Pfizer-BioNTech or Moderna vaccine, or 2 months after receiving a Johnson & Johnson vaccine.

COVID-19 causes symptoms that are similar to those of other types of respiratory illnesses. Typical symptoms of COVID-19 include:

Shortness of breath is more pronounced with COVID-19 compared with the seasonal flu or common cold.

Flu-like symptoms, such as chills or headache, are also possible with COVID-19. However, they may occur less often.

Other possible symptoms of COVID-19 include:

If you think you have symptoms of COVID-19, head home and stay there. Isolating yourself at home and staying away from other people can slow the transmission of the virus.

You’ll also want to:

  • Contact your doctor. Let your doctor know about your symptoms and get advice on what to do, including where and how to get tested.
  • Limit exposure to others. Limit your contact with others in your home. Avoid sharing household items with them.
  • Cover your nose and mouth. Use a face mask if you’re around others. Cover your mouth and nose with a tissue when you cough or sneeze. Discard the tissue and wash your hands right away.

As time passes, experts continue to learn more about the novel coronavirus, how it behaves, and how it’s transmitted.

Now that COVID-19 vaccines are available, public health and infectious disease experts continue to strongly recommend vaccination to everyone who’s eligible, which now includes children from ages 5 on up to older adults.

Additionally, it’s always a good idea to be proactive about handwashing and respiratory hygiene to give yourself the best shot at avoiding or spreading the coronavirus (or any other respiratory virus). The CDC also recommends wearing a mask indoors in areas with high COVID-19 cases.

If you do develop symptoms of COVID-19, call your doctor. This is especially important if you’ve been in contact with someone who already has COVID-19, or if you have symptoms that start getting worse.

A COVID-19 test can determine whether you have a coronavirus infection. If you do, you can take steps to isolate or begin treatments to get relief.