Coronavirus (COVID-19): Frequently Asked Questions


CORONAVIRUS: CDC Frequently Asked Questions and Answers

Disease Basics


Q: What is a novel coronavirus? 

A: A novel coronavirus is a new coronavirus that has not been previously identified. The virus causing coronavirus disease 2019 (COVID-19), is not the same as the coronaviruses that commonly circulate among humans and cause mild illness, like the common cold.

A diagnosis with coronavirus 229E, NL63, OC43, or HKU1 is not the same as a COVID-19 diagnosis. Patients with COVID-19 will be evaluated and cared for differently than patients with common coronavirus diagnosis.


Q: Why is the disease-causing the outbreak now being called coronavirus disease 2019, COVID-19?

A: On February 11, 2020 the World Health Organization announced an official name for the disease that is causing the 2019 novel coronavirus outbreak, first identified in Wuhan China. The new name of this disease is coronavirus disease 2019, abbreviated as COVID-19. In COVID-19, ‘CO’ stands for ‘corona,’ ‘VI’ for ‘virus,’ and ‘D’ for the disease. Formerly, this disease was referred to as “2019 novel coronavirus” or “2019-nCoV.”

There are many types of human coronaviruses including some that commonly cause mild upper-respiratory tract illnesses. COVID-19 is a new disease, caused by a novel (or new) coronavirus that has not previously been seen in humans. The name of this disease was selected following the World Health Organization (WHO) best practice for naming of new human infectious diseases.


Q: What is the name of the virus causing the outbreak of coronavirus disease starting in 2019?

A: On February 11, 2020, the International Committee on Taxonomy of Viruses, charged with naming new viruses, named the novel coronavirus, first identified in Wuhan, China, severe acute respiratory syndrome coronavirus 2, shortened to SARS-CoV-2.

As the name indicates, the virus is related to the SARS-associated coronavirus (SARS-CoV) that caused an outbreak of severe acute respiratory syndrome (SARS) in 2002-2003, however it is not the same virus.


Q: What is the source of COVID-19?

A: Coronaviruses are a large family of viruses. Some cause illness in people, and others, such as canine and feline coronaviruses, only infect animals. Rarely, coronaviruses that infect animals have emerged that can also infect people and spread between people. This is suspected to have occurred for the virus that causes COVID-19. Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS) are two other examples of coronaviruses that originated from animals and then spread to people. More information about the source and spread of COVID-19 is available on the Situation Summary: Source and Spread of the Virus.


Q: How does the virus causing Coronavirus Disease-2019 (COVID-19), spread?

A: Studies have shown that COVID-19 is spread very easily, mainly through close contact from person to person, including between people who are physically near each other (within about 6 feet). People who are infected but do not show symptoms can also spread the virus to others. Cases of reinfection with COVID-19 have been reported but are rare.


Q: Can someone who has had COVID-19 spread the illness to others?

A: The virus that causes COVID-19 is spreading from person-to-person. Someone who is sick with COVID-19 can spread the illness to others. Additionally, COVID-19 can be spread before a person displays symptoms. That is why CDC recommends that these patients be isolated either in the hospital or at home (depending on how sick they are) until they are better and no longer pose a risk of infecting others.

How long someone is actively sick can vary so the decision on when to release someone from isolation is made on a case-by-case basis in consultation with doctors, infection prevention and control experts, and public health officials and involves considering specifics of each situation including disease severity, illness signs and symptoms, and results of laboratory testing for that patient.

Current CDC guidance for when it is OK to release someone from isolation is made on a case by case basis and includes meeting all of the following requirements:

  • The patient is free from fever without the use of fever-reducing medications.
  • The patient is no longer showing symptoms, including cough.
  • The patient has tested negative on at least two consecutive respiratory specimens collected at least 24 hours apart.

Someone who has been released from isolation is not considered to pose a risk of infection to others.


Q: Can someone who has been quarantined for COVID-19 spread the illness to others?

A: Quarantine means separating a person or group of people who have been exposed to a contagious disease but have not developed illness (symptoms) from others who have not been exposed, in order to prevent the possible spread of that disease. Quarantine is usually established for the incubation period of the communicable disease, which is the span of time during which people have developed illness after exposure. For COVID-19, the period of quarantine is 14 days from the last date of exposure, because 14 days is the longest incubation period seen for similar coronaviruses. Someone who has been released from COVID-19 quarantine is not considered a risk for spreading the virus to others because they have not developed illness during the incubation period.


Q: Why might someone blame or avoid individuals and groups (create stigma) because of COVID-19?

APeople in the U.S. may be worried or anxious about friends and relatives who are living in or visiting areas where COVID-19 is spreading. Some people are worried about the disease. Fear and anxiety can lead to social stigma, for example, towards Chinese or other Asian Americans or people who were in quarantine.

Stigma is discrimination against an identifiable group of people, a place, or a nation. Stigma is associated with a lack of knowledge about how COVID-19 spreads, a need to blame someone, fears about disease and death, and gossip that spreads rumors and myths.

Stigma hurts everyone by creating more fear or anger towards ordinary people instead of the disease that is causing the problem.


Q: How can people help stop stigma related to COVID-19?

A: People can fight stigma and help, not hurt, others by providing social support. Counter stigma by learning and sharing facts. Communicating the facts that viruses do not target specific racial or ethnic groups and how COVID-19 actually spreads can help stop stigma.


Q: Is the coronavirus that causes COVID-19 the same as the MERS-CoV or the SARS-CoV virus?

A: No. Coronaviruses are a large family of viruses. Some coronaviruses cause cold-like illnesses in people. Others cause illness in certain types of animals, such as cattle, camels and bats. Rarely, animal coronaviruses can spread to people. This happened with SARS-CoV and MERS-CoV. The virus that causes COVID-19 likely also originated in an animal and spread to humans. The coronavirus most similar to the virus causing COVID-19 is SARS-CoV. There are ongoing investigations to learn more. The situation is changing, and information will be updated as it becomes available.




Q: If I have already had COVID-19 and recovered, do I still need to get vaccinated with a COVID-19 vaccine?

A: Yes. You should be vaccinated regardless of previous infection. Experts do not yet know how long you are protected from getting sick again after you had COVID-19. But studies have shown that vaccination provides strong protection for those who have previously had COVID-19. Visit the CDC website page to understand why getting vaccinated is a safer way to build protection than getting infected.

If you previously had COVID-19 and were given certain treatments, or if you have certain health conditions, such as multisystem inflammatory syndrome, visit the CDC website to learn more about clinical considerations for receiving the COVID-19 vaccine.


Q: Is it safe for my child to get a COVID-19 vaccine?

A: Yes. Studies show, and the CDC states, that COVID-19 vaccines are safe and effective. Like adults, children may have some regular side effects after COVID-19 vaccination that should disappear in a few days. Children 12 years and older should get a vaccine.


Q: Why should my child get vaccinated against COVID-19?

A: COVID-19 vaccination can help protect your child from getting infected, and, in turn, protect your family from being infected as well. The CDC recommends vaccination for everyone 12 years and older. Currently, the Pfizer-BioNTech COVID-19 vaccine is the only vaccine available to children 12 years and older.


Q: What are the ingredients in COVID-19 vaccines?

A: Vaccine ingredients can vary by manufacturer. To learn more about the ingredients in authorized COVID-19 vaccines, visit the links below:


Q: Do I need to wear a mask and avoid close contact with others if I am fully vaccinated?

A: No. The CDC say that fully vaccinated people can resume activities without wearing a mask or physically distancing, except where required by federal, state, local, tribal, or territorial laws and rules.


Q: Can I choose which COVID-19 vaccine I get?

A: Yes. All currently authorized and recommended COVID-19 vaccines are safe and effective. The CDC does not recommend one vaccine over another. Rather, the most critical decision is to get a COVID-19 vaccine as soon as possible in order to stop the spread of the pandemic.


Q: If I am pregnant, can I get a COVID-19 vaccine?

A: Yes. If you are pregnant, you can receive a COVID-19 vaccine. You may want to have a conversation with your healthcare provider to help you decide whether to get vaccinated. While such a conversation might be useful, it is not required before vaccination.

Visit the CDC website to learn more about vaccination considerations for people who are pregnant or breastfeeding and to learn about the v-safe tool that provides personalized health check-ins after vaccination.


Q: How long does protection from a COVID-19 vaccine last?

A: The CDC is not yet sure how long protection lasts for those who are vaccinated. However, we know that receiving the vaccine is a much safer choice than not receiving the vaccine and putting yourself and your loved ones at risk of serious illness and death.


Q: How many doses of COVID-19 vaccine will I need to get?

A: The number of doses needed depends on which vaccine you receive. To get the most protection:

The CDC states that if you receive a vaccine that requires two doses, you should get your second shot as close to the recommended interval as possible. However, your second dose may be given up to 6 weeks (42 days) after the first dose, if necessary. You should not get the second dose earlier than the recommended interval.


Q: If I have an underlying condition, can I get a COVID-19 vaccine?

A: People with underlying medical conditions can receive a COVID-19 vaccine as long as they have not had an immediate or severe allergic reaction to a COVID-19 vaccine or to any of the ingredients in the vaccine.

Visit the CDC website to learn more about vaccination considerations for people with underlying medical conditions.


Q: Can I get vaccinated against COVID-19 while I am currently sick with COVID-19?

A: No. People currently infected with COVID-19 should wait to be vaccinated until they have recovered from their illness and have met the criteria for discontinuing isolation. This guidance from the CDC also applies to people who get COVID-19 before getting their second dose of the vaccine.


Q: How do I get vaccinated in Missouri?

A: To receive your vaccine in Missouri, you should follow these steps:

  1. Register to receive your vaccine with the Missouri COVID-19 Navigator here.
  2. Find a provider near you here.
  3. Schedule an appointment directly with your provider.
  4. Visit the Missouri Health Department’s FAQ page for more information about the state’s vaccine distribution here.




Q: How can I help protect myself?

A: Visit the COVID-19 Prevention and Treatment page to learn about how to protect yourself from respiratory illnesses, like COVID-19.


Q: What should I do if I had close contact with someone who has COVID-19?

A: There is information for people who have had close contact with a person confirmed to have, or being evaluated for, COVID-19 available online.


Q: Does CDC recommend the use of a facemask in the community to prevent COVID-19?

A: CDC recommends that those who are not fully vaccinated and are aged 2 or older should wear a mask to protect themselves from COVID-19 in public settings. Wearing a mask in crowded outdoor settings and for activities with close contact with those who are not fully vaccinated is strongly suggested. Those that are fully vaccinated can resume activities without wearing a mask or social distancing, but must adhere to federal, state, local, tribal, or territorial laws, rules, and regulations, including local business and workplace guidance that require a mask. Those that are fully vaccinated and are immunocompromised should talk to their healthcare provider about managing health risks and may need to continue wearing a mask in order to protect themselves from COVID-19. CDC recommends that those who are not fully vaccinated continue to wear a mask and maintain social distancing.


Medical Information


Q: What are the symptoms and complications that COVID-19 can cause?

A: Current symptoms reported for patients with COVID-19 have included mild to severe respiratory illness with fever, cough, and difficulty breathing. Read about COVID-19 Symptoms.


Q: Should I be tested for COVID-19?

A: Testing is recommended for the following groups: people who have symptoms of COVID-19 (e.g. fever or chills, cough, shortness of breath, loss of taste or smell); people who had close contact with someone infected with COVID-19; and people who recently traveled or attended mass gatherings.

For those who are fully vaccinated, it is not necessary to be tested following close contact with a potential COVID-19 case, but the CDC still recommends testing if you exhibit any signs or symptoms of COVID-19. For people who have tested positive for COVID-19 within the past 90 days and recovered from the virus, it is not necessary to get tested unless you develop new symptoms.

If you get tested because you have symptoms or are unvaccinated and were potentially exposed to the virus, you should self-isolate pending test results and follow the advice of your health care provider or a public health professional.


Q: How do you test a person for COVID-19?

A: A viral COVID-19 test is conducted by taking a specimen from a nasal swab or a saliva sample. This test is analyzed in a lab to see if you are currently infected with SARS-CoV-2, the virus that causes COVID-19.

Tests have become increasingly available with the rapid spread of COVID-19 in the U.S. and around the world. You can contact your healthcare provider or visit your state, tribal, local, or territorial health department’s website to find the latest information on testing. Tests are available at many health centers and some pharmacies. Call in advance to see if an appointment is required. The type of viral COVID-19 tests (nasal swab or saliva sample) vary by location. If you already have symptoms of COVID-19 and if you are not able to be tested by a healthcare provider, you may consider either an at-home collection kit or an at-home test.

While waiting for your test results, you should self-quarantine at home and stay away from others, including those living in your household. If your test results are positive, isolate yourself. For more information, visit the CDC’s website pages for What to Do if You Are Sick and When to Quarantine.

There is a second type of test for COVID-19, called an antibody test, to check for previous infection. Antibody tests are available through healthcare providers and labs. You can check with your healthcare provider to see if they offer antibody tests. Regardless of your antibody test results, you should continue to take steps to protect yourself and others.


Q: Can a person test negative and later test positive for COVID-19?

A: Using the CDC-developed diagnostic test, a negative result means that the virus that causes COVID-19 was not found in the person’s sample. In the early stages of infection, it is possible the virus will not be detected.

For COVID-19, a negative test result for a sample collected while a person has symptoms likely means that the COVID-19 virus is not causing their current illness.


Q: What should healthcare professionals and health departments do?

A: For recommendations and guidance on persons under investigation; infection control, including personal protective equipment guidance; home care and isolation; and case investigation, see Information for Healthcare Professionals. For information on specimen collection and shipment, see Information for Laboratories. For information for public health professional on COVID-19, see Information for Public Health Professionals.


Public Health Response and Current Situation


Q: What is CDC doing about COVID-19?

A: This is an emerging, rapidly evolving situation and CDC will continue to provide updated information as it becomes available. CDC works 24/7 to protect people’s health. More information about CDC’s response to COVID-19 is available online.


Q: Am I at risk for COVID-19 in the United States?

A: This is a rapidly evolving situation and the risk assessment may change daily. The latest updates are available on CDC’s Coronavirus Disease 2019 (COVID-19) website.


COVID-19 and Animals


Q: What risks do animals or animal products imported from China pose?

A: CDC does not have any evidence to suggest that animals or animal products imported from China pose a risk for spreading COVID-19 in the United States. This is a rapidly evolving situation and information will be updated as it becomes available. The U.S. Centers for Disease Control and Prevention (CDC), the U. S. Department of Agriculture (USDA), and the U.S. Fish and Wildlife Service (FWS) play distinct but complementary roles in regulating the importation of live animals and animal products into the United States. CDC regulates animals and animal products that pose a threat to human health, USDA regulates animals and animal products that pose a threat to agriculture; and FWS regulates the importation of endangered species and wildlife that can harm the health and welfare of humans, the interests of agriculture, horticulture, or forestry, and the welfare and survival of wildlife resources.


Q: Should I be concerned about pets or other animals and COVID-19?

A: There is no current evidence that animals play a significant role in spreading SARS-CoV-2, the virus that causes COVID-19, to people and based on the available information to date, the risk of animals spreading COVID-19 to people is considered to be low. The exact source of the current outbreak of coronavirus disease 2019 (COVID-19) is unknown, but we know that it originally came from an animal, likely a bat and is now primarily spread from person-to-person. 

More studies are needed to understand if and how different animals could be affected by COVID-19 as coronaviruses that infect pets and other animals are rarely spread to people and then spread between people. However, since animals can spread other diseases to people, it’s always a good idea to wash your hands after being around animals. For more information on the many benefits of pet ownership, as well as staying safe and healthy around animals including pets, livestock, and wildlife, visit CDC’s Healthy Pets, Healthy People website


Q: Should I avoid contact with pets or other animals if I am sick with COVID-19?

A: You should restrict contact with pets and other animals while you are sick with COVID-19, just like you would around other people. A small number of pets worldwide, including cats and dogs, were reported to be infected with the virus that causes COVID-19, mostly after close contact with people with COVID-19. The risk of animals spreading COVID-19 to people is considered to be low. The virus that causes COVID-19 can spread from people to pets mostly during close contact. If a person inside the household becomes sick, isolate that person from everyone else, including pets and other animals.


Q: What precautions should be taken for animals that have recently been imported (for example, by shelters, rescue groups, or as personal pets) from China?

A: Animals imported from China will need to meet CDC and USDA requirements for entering the United States. As with any animal introduced to a new environment, animals recently imported from China should be observed daily for signs of illness. If an animal becomes ill, the animal should be examined by a veterinarian. Call your local veterinary clinic before bringing the animal into the clinic.


Q: Should I avoid animals and animal markets while I am traveling?

A: In the United States, there is no reason to think that any animals, including pets or livestock, might be a source of COVID-19 infection at this time. If you are visiting a live animal market anywhere in the world, it is important to clean your hands thoroughly with soap and water before and after visiting the market. Avoid contact with sick animals or spoiled products, as well as contaminated fluids and waste. Additional recommendations on basic protective measures are provided by WHO.