Frequently Asked Questions About COVID-19

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Vaccine Safety

Why should I get vaccinated for COVID-19?

COVID-19 can cause serious illness or even death. There’s no way to know how COVID-19 will affect you. And if you get sick, you could spread the disease to friends, family, and others around you, putting their lives at risk. Getting a COVID-19 vaccine greatly reduces the risk that you’ll develop COVID-19. The vaccines are highly effective against severe illness, hospitalization, and death due to COVID-19, including from the Delta variant.

The FDA has fully approved a COVID-19 vaccine after thoroughly evaluating data on its safety and effectiveness and inspecting manufacturing plants and procedures. The vaccine was authorized for emergency use late last year. If you’ve been waiting for an FDA-approved COVID-19 vaccine, you can get one today and help protect yourself and others.

Are the COVID-19 vaccines safe?

Yes. The COVID-19 vaccines available in the United States meet the FDA’s rigorous standards for safety and effectiveness. Tens of millions of people in the United States have received COVID-19 vaccines, and all COVID vaccines will continue to be monitored for safety.

Serious health effects from vaccines are very rare. It’s highly unlikely that COVID-19 vaccines will cause long-term health problems. Also, there is no evidence at all that they will cause infertility or cancer.

Your risk for serious health problems is much lower from the vaccine than your risk if you’re unvaccinated and get COVID-19. COVID-19 can leave you with heart and lung damage and other conditions that require long-term treatment. Vaccines are much safer paths to immunity than the disease itself.

How can COVID-19 vaccines be safe since they were developed so fast?

Safe COVID-19 vaccines were developed quickly through the use of a century of vaccine experience; technology that was new to vaccines but had been studied for two decades; a coronavirus vaccine already in development at the National Institutes of Health; and tens of thousands of volunteers for clinical trials that enabled rapid accumulation of data on safety and effectiveness. Simultaneous vaccine production and analysis of testing data also allowed vaccines to be shipped within days of FDA authorization.

Will the shot hurt or make me sick?

No. Some people might get sore muscles, feel tired, or have mild fever after getting the vaccine, but most people report only a sore arm where they got the shot. These reactions mean the vaccine is working to help teach your body how to fight COVID-19 if you are exposed. For most people, these side effects will go away on their own in a few days. If you have any concerns, call your doctor or nurse.

Can the vaccine give me COVID-19?

You can’t get COVID-19 from any of the COVID-19 vaccines in use or being tested in the United States because none of them contains the live virus that causes the disease.

Are the COVID-19 vaccines safe for people who are pregnant, trying to become pregnant, wanting to become pregnant someday or breastfeeding?

Growing evidence confirms that the available COVID-19 vaccines are safe and effective for people who are pregnant.

CDC recommends COVID-19 vaccination as soon as possible for all people who are pregnant, trying to become pregnant, wanting to become pregnant someday, or breastfeeding.

COVID-19 can be a dangerous disease during pregnancy and is known to present higher risks for severe illness if you are pregnant. COVID-19 during pregnancy also increases the risk of preterm birth and might increase risks for other adverse pregnancy outcomes. Getting a COVID-19 vaccine can protect you against severe illness from COVID-19 and help keep your baby safe.

Why are people having allergic reactions to the COVID-19 vaccines?

A few people have had allergic reactions called anaphylaxis after getting a COVID-19 vaccine but were treated and have recovered. Your doctor can help you decide if it’s safe for you to be vaccinated.

Are the COVID-19 vaccines safe for people with certain underlying medical conditions?

COVID-19 vaccines may be administered to most people with underlying medical conditions. If you have questions about getting a COVID-19 vaccine, talk with your health care provider. Inform your vaccination provider about all your allergies and health conditions.

Vaccine Effectiveness

How do COVID-19 vaccines work?

Vaccines train your immune system to recognize and fight the virus that causes COVID-19. With vaccines, you can build immunity to a disease without getting the disease.

How effective are the COVID-19 vaccines?

All available COVID-19 vaccines are highly effective against severe illness, hospitalization, and death due to COVID-19, including from the Delta variant.

Remember, to get the most protection from the vaccines, you need all the recommended doses:

  • The Pfizer-BioNTech and Moderna vaccines require 2 initial doses.
  • Johnson & Johnson’s Janssen vaccine requires 1 initial dose.

If you meet the criteria for having a compromised immune system, you should get a third dose of the Pfizer-BioNTech or Moderna vaccine at least 4 weeks after your second dose.

Why should I get vaccinated if I can still get infected with COVID-19?

It’s important to understand that infection doesn’t necessarily lead to illness. If you’re fully vaccinated against COVID-19 and the virus manages to enter your body and begins to multiply—that is, infect you—your immune system will be prepared to quickly recognize the virus and keep it from doing real damage. That’s why most people who get infected with COVID-19 despite being vaccinated—so-called breakthrough cases—have no symptoms (asymptomatic) or only mild-to-moderate illness.

Nearly everyone in the United States who is getting severely ill, needing hospitalization, and dying from COVID-19 is unvaccinated.

CDC recommends you get vaccinated as soon as you can.

How long do COVID-19 vaccines last?

Scientists don’t know right now how long COVID-19 vaccines protect people, but they are investigating this in medical studies.

Who can get a COVID-19 vaccine booster?

COVID-19 vaccines continue to work very well at preventing severe illness, hospitalization, and death.

But protection against infection appears to decrease over time.

A booster shot is an extra dose that helps keep up protection.

You’re eligible for a COVID-19 vaccine booster shot if:

  • It’s been at least 6 months since you got the second dose of a Pfizer-BioNTech or Moderna vaccine AND you’re any of the following:
    • At least age 65.
    • At least age 18 and have an underlying medical condition (such as asthma, diabetes, or obesity).
    • At least age 18 and are at increased risk for getting and spreading COVID because of where you live (such as a health care facility, college dormitory, or correctional facility).

    • At least age 18 and are at increased risk for getting and spreading COVID because of your job such as a health care worker, teacher, or grocery store worker).

OR:

  • You’re at least age 18 and it’s been at least 2 months since you got a dose of Johnson & Johnson’s Janssen vaccine.

If you're eligible for a booster, you may choose which vaccine to receive as a booster dose. Your booster shot doesn't have to be the same vaccine you received before.

For more information about boosters, or if you have questions about your eligibility, check out our booster resources or talk to a health care provider.

Note that a booster is not the same as the recommended third vaccine dose for people with compromised immune systems.

Do I need to get a COVID-19 vaccine if I’ve already had COVID-19?

Yes. Scientists don’t yet know how long natural antibodies in people who have had COVID- 19 will be protect them from being reinfected.

Will the COVID-19 vaccines prevent me from infecting others?

COVID-19 vaccines reduce the likelihood that you’ll develop and be able to spread COVID-19. In rare occasions, some vaccinated people can get COVID-19 from the highly contagious Delta variant and spread it to others. Importantly, only a very small amount of spread happening around the country comes from vaccinated individuals.

Do the vaccines work on the new COVID variants?

Scientists continue to study different forms, or variants, of the virus that causes COVID-19 to see if the vaccines will work against them. Current data suggest that all COVID-19 vaccines recommended for use in the United States offer protection against most variants, including the highly contagious Delta variant. For this reason, COVID-19 vaccines are an essential tool to protect people against COVID-19, including illness caused by the new variants. CDC will continue to monitor the impact these new variants may have on how well the vaccines work.

Vaccine Availability

When can I get a COVID-19 vaccine?

Vaccines are here now and everyone age 12 and older can get them. You have three ways to find vaccines near you:

  • Go to vaccines.gov
  • Text your ZIP code to 438829
  • Call 1-800-232-0233

How much will a COVID-19 vaccine cost?

The federal government is providing the vaccine free of charge to all people in the United States.

Do I need to wear a mask after getting vaccinated?

If you’re fully vaccinated, you can participate in many of the activities that you did before the pandemic. To maximize protection from the highly contagious Delta variant and prevent possibly spreading it to others, wear a mask inside public places if you’re in an area of substantial or high spread of COVID-19.

If you’re not yet vaccinated, you should continue to:

  • Wear a mask when inside public places.
  • Keep at least 6 feet part from people who don't live with you and who may not be vaccinated.
  • Avoid crowds.
  • Avoid poorly ventilated spaces.
  • Wash your hands often with soap and water for at least 20 seconds or use hand sanitizer with at least 60% alcohol when soap and water aren’t available.

Vaccinated and unvaccinated people must still follow federal, state, local, tribal, and territorial laws, rules, and regulations. That includes public transportation, airport/airplane, local business, and workplace guidance.

Do people with compromised immune systems need extra doses of a COVID-19 vaccine?

People with compromised immune systems are less able to fight infections. If any of the following apply to you, you may not be fully protected from COVID-19 even if you’ve received two doses of Pfizer-BioNTech’s or Moderna’s mRNA COVID-19 vaccine:

  • You have a moderate or severe primary immunodeficiency disorder, such as DiGeorge syndrome or Wiskott-Aldrich syndrome.
  • You have an advanced or untreated HIV infection.
  • You’ve ever had an organ transplant or had a stem cell transplant within the last 2 years.
  • You’re being treated with corticosteroids or other immunosuppressant medicines for such conditions as arthritis, asthma, or an autoimmune disease, such as lupus, sarcoidosis, inflammatory bowel disease, rheumatoid arthritis, and psoriasis.
  • You’re being treated for cancer.

To get the most benefit from the mRNA COVID-19 vaccines, people with compromised immune systems should get a third dose. Wait at least 4 weeks after you get your second dose to get your third dose.

You should also continue to follow current COVID-19 prevention measures until your health care provider says it’s safe for you to stop:

  • Wear a mask that covers your nose and mouth around people you don’t live with and when inside public places.
  • Stay at least 6 feet apart from people you don’t live with.
  • Avoid crowds and poorly ventilated indoor spaces.
  • Wash your hands often with soap and water for at least 20 seconds or use hand sanitizer with at least 60% alcohol when soap and water aren’t available.

SAFETY IS THE TOP PRIORITY
 

The FDA and CDC have the highest standards when it comes to ensuring the safety and effectiveness of vaccines. Their process includes the following procedures:
  • Scientists must first test vaccines extensively in medical studies to ensure they are safe and effective.
  • Before the FDA authorizes a vaccine for use among the public, it ensures its safety by independently:

    • Reviewing the data from the medical studies, and
    • Inspecting the manufacturing facilities.
  • Even after a vaccine has been authorized, the FDA and CDC closely monitor vaccine administration to identify even rare side effects or reactions.
  • The FDA and CDC closely review any reports of side effects or reactions and share these facts with the public.

The extremely rare cases of blood clotting and Guillain-Barré Syndrome following Johnson & Johnson’s Janssen vaccine and heart inflammation following Pfizer-BioNTech’s and Moderna’s vaccines—a very small number of cases out of millions of vaccinations—show that the FDA and CDC’s vaccine safety monitoring systems work and catch even the rarest reactions.

Thorough investigations have confirmed that all three available vaccines are safe and effective. Medical experts stress that the benefits of receiving any of the COVID-19 vaccines in use in the United States far outweigh any potential risks.

The monitoring systems ensure that doctors are notified to watch for signs of serious reactions, no matter how rare, and are aware of proper courses of treatment.

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