COVID-19

Frequently Asked Questions about COVID-19

COVID-19 is a contagious disease caused by the SARS-CoV-2 virus. Most people with COVID-19 have mild symptoms, but some may become severely ill.

Who is at greatest risk of serious illness from COVID-19?

Although COVID-19 can affect anyone, individuals at greater risk of severe illness from COVID-19 include the following:

Older adults
People with certain medical conditions like cancer, chronic kidney disease, chronic lung disease, dementia, diabetes (type 1 or type 2), Down syndrome, heart disease, HIV, liver disease, and sickle cell disease
Those living in a nursing home or long-term care facility
Obesity (body mass index [BMI] >30)
Pregnant women
Smokers
Those who have a weakened immune system

Are you contagious before you develop symptoms?

COVID-19 can be spread before symptoms develop, which can pose a problem because people who do not know they are infected may continue to go to work, school, and other public places. People who are sick and have symptoms are more likely to stay home, creating fewer opportunities for the virus to spread from one person to another.

If you have COVID-19, it’s important to avoid spreading the virus to others.

How can you tell the difference between COVID-19 and a cold or influenza (flu)?

Symptoms of COVID-19 may include fever, cough, and shortness of breath. Because the symptoms are similar to those of cold and flu, it can be difficult to distinguish between COVID-19 and other respiratory viruses. To diagnose a potential case, healthcare professionals may use a COVID-19 diagnostic test and/or run tests to rule out flu and other infections.

Individuals with COVID-19 have had a wide range of symptoms, ranging from mild to severe illness. Some individuals who are infected may not have symptoms, others require ventilator support, and many have died. Symptoms may appear 2-14 days after exposure to the virus and may include:

Fever
Cough
Shortness of breath or difficulty breathing
Chills
Fatigue
Muscle pain or body aches
Headache
Sore throat
Loss of taste or smell
Congestion or runny nose
Nausea or vomiting
Diarrhea

What should I do if I think I have COVID-19?

If you have been exposed to COVID-19 and you have symptoms, get tested immediately. If you have been exposed but do not have symptoms, you should wait at least 5 full days after exposure before getting tested. Testing too early can give you a false result.

Getting tested for COVID-19 can help determine if treatment is appropriate to reduce your risk of severe illness as well as steps to take to lower your chances of spreading the virus to others.

If you test positive for COVID-19, contact a healthcare professional to see if antiviral treatment is right for you. In addition, stay home, manage your symptoms, and take precautions to help protect others from getting infected.

If you have trouble breathing or other emergency warning signs, seek medical care immediately.

You may return to normal activities when, for at least 24 hours:

Your symptoms are improving overall, and
You no longer have a fever without using a fever-reducing medication

What is long COVID?

Long COVID, also known as post-COVID conditions (PCC), includes a wide range of long-term health issues that can occur in people who have been infected with SARS-CoV-2, the virus that causes COVID-19.

The symptoms of long COVID may vary from one person to another and can last weeks, months, or even years following infection. These symptoms may be hard to explain or manage and, in some cases, can lead to disability.

Vaccination

Who should get vaccinated?

The Centers for Disease Control and Prevention (CDC) recommends a 2024-2025 COVID-19 vaccine for most adults age 18 years or older.

It is especially important to get a 2024–2025 COVID-19 vaccine if you are age 65 or older, are at high risk for severe COVID-19, or have never received a COVID-19 vaccine.

For adults age 65 years and older and those who are moderately or severely immunocompromised, CDC recommends a second dose of 2024-2025 COVID-19 vaccine, to be given 6 months after the first dose.

Parents of children ages 6 months-17 years should talk with a trusted healthcare professional about COVID-19 vaccination.

Who should not get vaccinated?

COVID-19 vaccines are safe for most people, with few exceptions:

Current vaccines are not authorized for children younger than age 6 months
People who have a severe allergic reaction after receiving a COVID-19 vaccine or have an allergy to a component in the vaccine should not receive that vaccine type and should consult a healthcare professional with expertise in allergy or immunology

If I already had COVID-19, do I still need to get vaccinated?

Will COVID-19 vaccines work against new variants?

What are common side effects from the vaccine?

Side effects may include a sore arm, pain, swelling or redness at the injection site, fever, fatigue, or other symptoms. These symptoms are normal, should be expected, and are a sign that the body is building immunity. These side effects usually only last a few days.

Over-the-counter medicines, such as aspirin, anti-inflammatories, or acetaminophen, may help relieve fever, pain, or discomfort after getting vaccinated—but should not be used before getting vaccinated. To reduce pain and discomfort in the arm, apply a clean, cool, wet washcloth over the area, and use/exercise your arm gently.

How do we know that the vaccines are safe?

All vaccines used in the US are required to go through extensive safety testing before they are authorized or licensed by the US Food and Drug Administration (FDA) and recommended for widespread use by the Centers for Disease Control and Prevention (CDC). Since the start of the pandemic, billions of doses of COVID-19 vaccines have been administered in the US and globally.

All COVID-19 vaccines continue to undergo extensive safety monitoring, including using several reporting systems to ensure the safety of COVID-19 vaccines. Serious side effects from the vaccines are rare and are significantly milder than the diseases they prevent.

Is it safe to get a COVID-19 vaccine while pregnant or breastfeeding?

Yes, COVID-19 vaccination is safe for women who are pregnant, breastfeeding, trying to get pregnant, or might become pregnant to prevent them from getting severely ill with COVID-19. Vaccination during pregnancy also protects infants from severe COVID-19 before they are old enough to be vaccinated.

There has been no evidence that COVID-19 vaccines are harmful to either women who are breastfeeding or to their babies.

Are COVID-19 vaccines safe for people with chronic health conditions?

Multiple studies show that older adults and those with certain medical conditions—including cancer, chronic kidney disease, chronic lung disease, dementia, diabetes (type 1 or type 2), Down syndrome, heart disease, HIV, liver disease, and sickle cell disease—are at higher risk of severe illness or death from COVID-19 and should be vaccinated. COVID-19 vaccines remain the best way to prevent hospitalization, long-term health outcomes, and death.

Do COVID-19 vaccines interfere with other medications?

Can I still get COVID-19 after getting vaccinated?

Although vaccination helps protect against severe disease and related complications including hospitalization and death, iy may not be as effective in preventing mild COVID-19 infections.

It typically takes a few weeks for the body to build immunity after vaccination, so it is possible to be infected with the virus that causes COVID-19 before or after vaccination.

Since COVID-19 vaccines do not contain live virus, it is not possible to get the disease from the vaccine.

Updated July 2025

Sources: American Academy of Pediatrics, Centers for Disease Control and Prevention, Food and Drug Administration

Related Resources

Real Stories, Real People

Maria’s Story (COVID-19)

Maria was a healthy, active 41-year-old who contracted COVID-19 before vaccines were available, and is now a severe COVID-19/ECMO survivor and a vaccine advocate

Learn More