10 Things to Know About Coronavirus

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illustration of coronavirus, image credit Alissa Eckert and Dan Higgins from the Centers for Disease Control and Prevention
Alissa Eckert, MS; Dan Higgins, MAM

The first diagnosis of the respiratory disease caused by the novel (new) coronavirus was in Wuhan in Hubei Province, China in December of 2019. Since the World Health Organization declared a pandemic on March 11, 2020, the number of confirmed cases has topped 161 million, including 32 million cases in the United States. (Image credit: illustration of coronavirus, Alissa Eckert and Dan Higgins from the U.S. Centers for Disease Control and Prevention.)

For the most current data and prevention guidance, contact your state's health department, visit the CDC website, or refer to this list of CDC and other resources.

Here’s what you need to know about the novel coronavirus:

1. The novel coronavirus is SARS-CoV-2 and the disease is COVID-19.

SARS-CoV-2 stands for Severe Acute Respiratory Syndrome-Coronavirus-2, because the virus is very similar to the SARS coronavirus first discovered in 2003. The SARS-CoV-2 disease is COVID-19, for Coronavirus Disease 2019.

2. The first cases in the United States were mainly in people who traveled from China.

Some of the first known cases of COVID-19 in the United States were in people returning from travel abroad, from China, cruise ships, and subsequently from other countries with COVID-19 spread. These are so-called “imported” cases. On February 25, 2020, the CDC diagnosed the new coronavirus disease in a person who lives in California but who had no known travel history or close contact with an infected person. These are "community" cases because they did not arise from a known source. 

3. The novel coronavirus spreads very easily from person to person.

SARS-CoV-2 spreads through tiny respiratory droplets from the nose or mouth when an infected person coughs or sneezes. You can contract the coronavirus if these droplets land in your nose or mouth, you inhale them, or you touch a contaminated surface or object and then touch your nose or mouth before washing your hands. The virus also spreads through the air under certain circumstances, such as in enclosed spaces with poor ventilation.

Infected people are contagious before symptoms develop. That is presymptomatic transmission. Studies show the virus multiplies fast in the nose and throat, even in the beginning of an infection when the person does not yet feel ill. Infectious disease experts estimate about 20% of infected people never develop symptoms. Asymptomatic (and presymptomatic) individuals still shed the virus and are capable of infecting others.

4. Social distancing and wearing a mask helps slow the spread of infection.

You can do your part to slow the spread of COVID-19 by social distancing, which is avoiding large public gatherings and keeping a distance of at least 6 feet from other people. Because the virus can spread through the air in poorly ventilated, crowded spaces, you should avoid indoor public spaces to limit possible exposure. Wearing a cloth or disposable surgical mask over your mouth and nose helps limit the amount of respiratory droplets you release into the environment when you talk, sneeze and cough. A mask also offers some protection to you.

Everyone wearing a mask in indoor public spaces reduces person-to-person transmission of the virus. That is because you could be infected and not know it; wearing a mask reduces the chance of unknowingly spreading the virus to others. Masks are also important outside where you may encounter other people and you cannot maintain a social distance of at least 6 feet. If you have already received the COVI-19 vaccine (see #7), you do not need to wear a mask or physically distance in any setting, according to the CDC, unless required to do so by a governing body, business, or workplace.

5. COVID-19 symptoms range from mild to severe and it can be fatal.

The common cold is also spread by a coronavirus (as well as other types of viruses). For some patients, coronavirus symptoms mimic those of a common cold, while others experience the same symptoms that accompany a severe respiratory infection. COVID-19 symptoms include fever, cough, body aches, sore throat, fatigue, phlegm/sputum production, and shortness of breath. An unexpected symptom of COVID-19 is loss of sense of smell. In some cases, the virus attacks the lungs and symptoms are severe enough the patient requires hospital care with supplemental oxygen and fluids, even breathing support with a ventilator. COVID-19 symptoms appear within 2 to 14 days after exposure.

The risk of dying from COVID-19 is greater in people who have underlying chronic health conditions, such as obesity and/or heart, lung or liver disease.

6. The FDA approved the first targeted COVID-19 treatment.

The FDA (Food and Drug Administration) recently approved the antiviral drug, remdesivir (Veklury), for use in hospitalized COVID-19 patients. The drug is not specific for SARS-CoV-2, but it has been shown to speed up recovery time in clinical studies.

The FDA also approved the first targeted COVID-19 treatment, a monoclonal antibody (Mab) called bamlanivimab, for patients with mild-to-moderate COVID-19 at risk for severe disease. The drug is specific for the virus's spike protein, interfering with how the virus infects cells. The Mab cocktail former President Trump received has also been approved for high-risk patients with mild-to-moderate COVID-19.

Research and development continues on other treatments; many drugs are in clinical trials. In the meantime, hospitalized patients receive appropriate treatment for serious respiratory symptoms and other disease complications. The death rate of COVID-19 has decreased significantly since the pandemic first started, largely because doctors worldwide are learning more about the disease and when (and if) to deliver specific treatments.

7. There are three authorized COVID-19 vaccines.

Two COVID-19 vaccines were authorized for emergency use by the FDA in late 2020, and a third in late February 2021. All three vaccines are highly effective in preventing COVID-19 and saving lives. The COVID-19 vaccine from Pfizer-BioNTech is authorized for people ages 12 and older. The vaccines from Moderna and Janssen (a Johnson & Johnson company) are authorized for people ages 18 and older. The vaccine is free to anyone who is eligible to receive it.

8. The source of the novel coronavirus is linked to animals.

Because many patients in the Wuhan, China outbreak were linked to a large seafood and animal market, the 2019 coronavirus was thought the virus spread directly from animals to humans. However, once in humans, the virus was able to spread person to person. This is similar to the spread of two other coronaviruses that originated from animals: SARS-CoV (civet cats) and MERS-CoV (camels). There are many different coronaviruses. They mainly infect animals, but some of the viruses can spread from animals to humans. This is the case with SARS-CoV, MERS-CoV, and the new coronavirus (SARS-CoV-2): All three viruses came from bats.

9. The novel coronavirus is mutating.

Variations, or mutations in the novel coronavirus are occurring on a regular basis, as the virus passes from person to person. This is normal for coronaviruses and many other viruses. In most cases, mutations have little effect. In others, they can have a dramatic effect, like the variant first discovered in the United Kingdom. The U.K., or B.1.1.7 variant, spreads 30 to 50% faster than the original virus; it also causes more severe disease. B1.1.7 is the most common source of new U.S. COVID-19 cases.

How well the COVID-19 vaccines protect against infection and disease caused by known variants depends on several factors, such as the specific vaccine and variant in question and severity of illness. Researchers are optimistic the COVID-19 vaccines will protect against disease caused B.1.1.7, but vaccines may be less effective against other variants, such as the Brazil and South Africa variants. In clinical trials, Johnson & Johnson's COVID-19 vaccine protected people from severe disease caused by the South Africa variant, but it was less effective at preventing "moderate" COVID-19.

New, variant-specific vaccines are in development at several vaccine companies. Requiring a booster shot of a variant-specific vaccine is analogous to getting an annual flu shot.

10. Get tested for COVID-19 if you have symptoms.

If you have symptoms of COVID-19, contact your doctor about getting tested for the virus. The U.S. Department of Health and Human Services has a list of no-cost testing sites by state. If you were close (within 6 feet for more than 15 minutes) to someone who has COVID-19, contact a healthcare provider about what type of diagnostic COVID test to take and when.

Keep in mind there is an incubation period for the virus. Even if you got infected, your COVID test will be negative until you have enough virus to be detected (regardless of symptoms). It's best to wait about five days from the time of close contact to take the test. If possible, stay home and avoid in-person contact (quarantine), while monitoring yourself daily for signs and symptoms of COVID-19. Call your healthcare provider if you develop serious symptoms, including difficulty breathing. (If you get tested and the result is negative, you may end quarantine after 7 days, as long as you did not develop COVID symptoms during quarantine.)

For the most recent information about COVID-19, check the CDC website for updates, including the number of confirmed cases and advice for travelers. Call your state's public health department for local information. Some states have set up phone hotlines. 

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Apr 26
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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