Jan 11, 2021, 4:42:33 PM CST Jan 6, 2022, 12:21:01 PM CST

COVID-19 vaccine FAQs

Learn the facts about COVID-19 vaccines and what they mean for the health of your family


As more people get vaccinated against COVID‑19, many people are hopeful that we're one step closer to ending the pandemic. But there are also many questions about the vaccines, such as how do they work, are they safe and who should get vaccinated.

We've addressed some common questions and myths to help you and your family. For the most up-to-date information about the COVID‑19 vaccines, visit the Centers for Disease Control and Prevention (CDC) website.

When did the COVID‑19 vaccine become available?

In December 2020, the Food and Drug Administration (FDA) granted emergency use authorization to two COVID‑19 vaccines, one developed by Pfizer and BioNTech and another developed by Moderna. A third COVID‑19 vaccine, developed by Johnson & Johnson/Janssen, was granted emergency use authorization on February 27, 2021.

The Pfizer-BioNTech vaccine now has full FDA approval for children 16 and older and emergency authorization for ages 5-15. This means that any child over the age of 5 is now eligible to get vaccinated.

When will my family be able to get the COVID‑19 vaccine?

Adult getting vaccineAnyone ages 5 years and older can now get the Pfizer-BioNTech COVID‑19 vaccine. You can visit vaccines.gov to find a COVID‑19 vaccine near you.

Currently, the Moderna and Johnson & Johnson COVID‑19 vaccines are approved for use in people 18 years and older. 

Clinical trials are currently studying the COVID-19 vaccine in children as young as 6 months old. It is not yet known when the vaccine will be approved for children under age 5.

How does the COVID‑19 vaccine work?

Vaccines work by helping our bodies develop immunity to a virus. Many vaccines, such as the flu vaccine, do this by putting weakened or inactivated virus particles into the body to trigger an immune response. The COVID‑19 vaccines work differently.

Both the Pfizer-BioNTech and Moderna COVID‑19 vaccines are messenger RNA (mRNA) vaccines. This is a type of vaccine that uses mRNA to teach our cells how to make a protein (called a spike protein) that is found on the surface of the virus that causes COVID‑19. This protein triggers an immune response which produces antibodies. These antibodies protect us if we are exposed to the actual virus. While the COVID‑19 vaccines are the first approved vaccines to use mRNA technology, mRNA vaccines have been researched for decades. They have also been tested to ensure safety. Learn more about how mRNA vaccines work.

The Johnson & Johnson vaccine is a viral vector vaccine. This type of vaccine uses a “vector,” or a modified, harmless version of a different virus, to teach our bodies how to protect us from the virus that causes COVID‑19. Learn more about viral vector vaccines.

COVID‑19 Vaccine Myths & Facts
Myth: The COVID‑19 vaccine can alter my DNA.
Fact: mRNA does not affect or change a person's DNA or genetic makeup in any way. The mRNA from the COVID‑19 vaccine does not enter the nucleus of the cell, which means it cannot interact with DNA.

How many doses of the COVID‑19 vaccine do you need?

Both the Pfizer and Moderna vaccine require two doses to be effective. The Pfizer vaccine requires a second shot 21 days after the first. The Moderna vaccine requires a second shot 28 days later. The Johnson & Johnson vaccine only requires one dose.

It's important to know that it takes time for the body to develop immunity after getting the COVID‑19 vaccine. It may take a week or two after your final dose of the vaccine to become protected.

The CDC recommends those who are moderately to severely immunocompromised should receive an additional dose of mRNA COVID‑19 vaccine after the initial two doses. An additional dose should be administered at least 28 days after a second dose.

In addition, the CDC recommends that everyone who is eligible should get a booster shot. Learn more about COVID‑19 booster shots and who is eligible.

Is the COVID‑19 vaccine safe?

Safety is a top priority for the COVID‑19 vaccines. The COVID‑19 vaccines have gone through rigorous clinical trials and approvals to determine that they are safe and effective. In addition, it's been shown that the benefits of receiving a COVID‑19 vaccine far outweigh any potential risk. The COVID‑19 vaccines protect you and others from the potential dangers of COVID‑19 infection.

Experts are closely monitoring the safety of the vaccines as they are distributed. Since they've been approved, millions of people have safely received a COVID‑19 vaccine. There have been some reports of immediate allergic reaction to the vaccine, but these reactions are quite rare.

You may have heard about rare COVID‑19 vaccine side effects called myocarditis and pericarditis, or heart inflammation. Experts who are closely monitoring safety of the COVID‑19 vaccine recommend that anyone who is eligible can and should continue to get vaccinated. Learn more about the COVID‑19 vaccine and your heart.

The CDC and FDA also reviewed cases of blood clots that developed in individuals after receiving the Johnson & Johnson vaccine. These adverse events appear to be extremely rare, and the vaccine was approved as safe for continued use. See more details from the CDC.

If any other unanticipated side effects are detected, there will be updates to vaccine recommendations to continue to ensure your safety.

COVID‑19 Vaccine Myths & Facts
Myth: The COVID‑19 vaccine can't be safe because it was developed so quickly.
Fact: Before receiving approval for use, manufacturers had to show data from large clinical trials to ensure that the vaccines were safe and effective. The emergency nature of the pandemic required a quick response, but thorough safety standards were still required and met.

Is there anyone who should not receive the COVID‑19 vaccine?

Anyone with a severe allergy to any of the ingredients in the COVID‑19 vaccines should not receive the vaccine. In addition, anyone with an allergy to polyethylene glycol (PEG) or polysorbate should not receive the vaccine. If you've had an allergic reaction to another vaccine, check with your health care provider before receiving the vaccination.

People with other allergies, including food allergies, can receive the COVID‑19 vaccine. If you are immunocompromised, pregnant or breastfeeding, you can also still receive the COVID‑19 vaccine. There is no evidence that the COVID‑19 vaccine affects fertility, and the vaccine is safe for persons who are trying to get pregnant. Talk with your health care provider if you have specific questions about if it is safe for you to get vaccinated.

COVID‑19 Vaccine Myths & Facts
Myth: I can't get the COVID‑19 vaccine if I have a food allergy or am immunocompromised, pregnant or breastfeeding.
Fact: You can still get vaccinated if you have food allergies, existing health conditions, or are pregnant or breastfeeding. The vaccine can help protect you from the dangers of COVID‑19 infection.

What are the side effects of the COVID‑19 vaccine?

You may experience some side effects after receiving the COVID‑19 vaccination. These side effects are normal signs that your body is building protection or immunity against the virus. Common side effects of the COVID‑19 vaccine can include:

  • Pain, redness or swelling at the injection site
  • Fever
  • Chills
  • Tiredness
  • Headache
  • Muscle pain
  • Nausea

For vaccines requiring a second dose, side effects may be more common after the second dose than the first dose. These side effects should go away within a few days after immunization. You can also ask your doctor about taking ibuprofen and acetaminophen after vaccination to help relieve pain or discomfort.

Can I get COVID‑19 from the vaccine?

You cannot get COVID‑19 from the vaccine. It can take a few weeks to build immunity after you get the vaccine, so it is possible to become infected with COVID‑19 just before or after you get your shot.

COVID‑19 vaccines will not cause you to test positive on a COVID‑19 viral test, which is used to check for a current infection. As your body develops an immune response, there is a possibility you may test positive on some antibody tests. Antibody tests are designed to tell if you had a previous infection because they indicate some level of protection against the virus. Experts are learning more about how the COVID‑19 vaccine may affect antibody testing.

COVID‑19 Vaccine Myths & Facts
Myth: The COVID‑19 vaccine can give me COVID‑19.
Fact: It is not possible for the COVID‑19 vaccine to give you COVID‑19. You may experience some side effects after the vaccine. These are a normal sign your body is developing protection against the virus. It takes a few weeks for your body to build immunity after vaccination, which means it is possible for you to get COVID‑19 just before or after you get a COVID‑19 vaccine.

If I've had COVID‑19, should I get the vaccine?

Even if you've had COVID‑19, there are still benefits to getting the vaccine. We do not yet know how long someone is protected against COVID‑19 after infection (called natural immunity). Because reinfection with COVID‑19 is possible, it is still recommended that you receive a vaccine.

If you are currently infected with COVID‑19, you should wait until symptoms resolve and you are done isolating to receive the vaccination. Experts are still learning more about natural immunity, as well as how long the vaccine will provide immunity. Recommendations will be updated as they learn more.

COVID‑19 Vaccine Myths & Facts
Myth: If I've had COVID‑19, I don't need to get the COVID‑19 vaccine.
Fact: If you've already had COVID‑19, there are still benefits to receiving the COVID‑19 vaccine. It is not known how long natural immunity lasts, and the vaccine can protect you from reinfection.

Should I still wear a face mask after getting vaccinated?

As experts continue to learn more about COVID‑19 and the vaccines, we should take every step we can to stop the pandemic. The CDC recommends that fully vaccinated individuals continue to wear a face mask when in public indoor places in areas with high or substantial COVID‑19 transmission (see map here). This is to maximize protection from the highly contagious Delta variant.

If you are immunocompromised, you may not be fully protected even if you are fully vaccinated. Talk with your health care provider about precautions to take such as wearing a mask.

Once you're fully vaccinated, there are some activities you can start to do safely. Learn more about recommendations for life after vaccination. Experts will continue to monitor the spread of COVID‑19 and how many people get vaccinated. They will adjust any recommendations when it is safe to do so.

COVID‑19 Vaccine Myths & Facts
Myth: I can stop wearing my mask once I've received my COVID‑19 vaccine.
Fact: If you are fully vaccinated, wear a mask indoors in public if you are in an area of substantial or high transmission. Experts are still learning more about how the vaccines work in real‑life conditions and may update recommendations when it is safe to do so.

The COVID‑19 vaccines are an important and exciting step in ending the coronavirus pandemic. The vaccines can help prevent illness and may also protect others around you.

For more information about the COVID‑19 vaccine, watch a video of our virtual town hall.

MYTH: COVID-19 vaccines mean we can stop wearing masks. FACT: Masks should be worn in public indoor places in areas with high transmission. @Childrens shares the facts about vaccines here.

Learn more

Children's Health℠ is committed to remaining a trusted source of health information and care for you and your family during this time. See more resources to keep your family healthy at the Children's Health COVID‑19 hub.

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