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COVID-19 Vaccine FAQs

The University of Maryland School of Medicine’s (UMSOM) Center for Vaccine Development and Global Health (CVD) has been at the forefront of COVID-19 vaccine research. As COVID-19 vaccine rollout proceeds across the U.S., we offer answers to frequently asked questions.

What are bivalent boosters, and why are they recommended?

Bivalent boosters add Omicron BA.4 and BA.5 to the current vaccine makeup to create a new version of the booster. Experts hope this will be more effective against current and future circulating COVID-19 variants. 

People ages 12 and older may receive bivalent Pfizer-BioNTech boosters. Bivalent boosters made by Moderna are available for people ages 18 and older.

Updated COVID-19 boosters for other pediatric groups are expected to be authorized soon.

Now that vaccines are available for the youngest children, how do I know if it is safe for my son or daughter?

Rest assured that COVID-19 vaccines were extensively studied before the Food and Drug Administration issued Emergency Use Authorizations (EUA). However, it is totally understandable to ask questions before deciding whether to vaccinate your child.

Here is what we know: The Moderna and Pfizer vaccines for children under age 5 received EUA in June 2022. This means that everyone age 6 months and older should receive COVID-19 vaccines, according to the CDC.

Both vaccines are safe and effective. The key difference: Pfizer's primary vaccine series for children ages 6 months to 4 years old requires three shots to achieve the expected immunity, and Moderna's vaccine for the same age group requires two shots.

The COVID-19 vaccine has been available for children and teens ages 5 through 17 years for some time, and millions in this age group have received at least one vaccine dose. Through the Vaccine Adverse Event Reporting System, the FDA and CDC monitor vaccine safety and will continue to do so going forward for all age groups.

Learn more:

I'm vaccinated & am a close contact of a friend with COVID-19. I also recovered from a COVID-19 infection about a month ago. What should I do?

Per updated CDC guidance in August 2022, instead of quarantining if you were exposed to COVID-19, you may wear a high-quality mask for 10 days and get tested on day 5.

If you test positive for COVID-19, the guidelines are specific to the severity of illness and duration of symptoms. For specific information, read the CDC's quarantine and isolation guidance.

I know several people who recently had COVID. I'd like to protect myself and my vulnerable loved ones. What do we know about how COVID-19 spreads?

COVID-19 is spread in three main ways, according to the CDC. This includes:

  • Breathing in air from a nearby infected person.
  • Having the small droplets and particles exhaled by that person land on your eyes, nose, or mouth, particularly if the infected person coughs or sneezes.
  • Touching your eyes, nose, or mouth with hands that have the COVID-19 virus on them.

What are COVID-19 Communty Levels, and what do they mean to me?

The CDC developed COVID-19 Community Levels to help communities decide which prevention steps are necessary, based on data. The three levels are low, medium, or high -- calculated via the percentage of hospital beds used by COVID-19 patients, rate of new hospital admissions, and the rate of new, local COVID-19 cases.

Check your COVID-19 Community Level. Also, learn which steps are recommended for each community level. 

How can I find at-home COVID-19 tests? How do I know if I should test myself?

Check with local health departments, which may also offer free tests. 

You may also buy COVID tests in pharmacies and retail stores. Your health insurance may offer reimbursement for purchasing these tests. Visit FDA’s website for a list of authorized at-home tests to ensure you get a valid test.

You should test for COVID-19:

  • after you develop symptoms, such as fever, sore throat, runny nose, or loss of smell or taste. 
  • at least 5 days after you were a close contact of someone with COVID-19
  • when you’re going to a gathering, especially if the group includes people at risk for severe disease, or people who are not up to date on their COVID vaccines. 

Are COVID-19 vaccines safe?

Millions of Americans have received COVID-19 vaccines, which are safe and effective and undergo intense safety monitoring. Learn more.

Should people with allergies receive COVID-19 vaccines?

People with allergies to foods, drugs, or other ingredients that are not in the vaccine can receive it. But people who have had an allergy to polyethylene glycol (abbreviated PEG), an mRNA vaccine component, or to another ingredient called polysorbate, should not receive the Moderna or Pfizer vaccines. Those who have had reactions to a vaccine or injectable therapy that contains multiple components – such as PEG or polysorbate – but are unsure which component caused the allergic reaction have a precaution to vaccination, so they should consult with their doctors prior to receiving the vaccine.

Where can I find the list of ingredients for each vaccine?

Will I have side effects from the COVID-19 vaccine?

Side effects following vaccination are usually mild and last a short time. In fact, experiencing side effects is a sign that your body is working hard to build protection for you. Common side effects include: arm soreness, redness and swelling, and tiredness, headache, muscle pain, chills, fever, and nausea. Learn more on the CDC’s website.

Should I receive a COVID-19 vaccine if I am pregnant or breastfeeding?

Yes, the CDC recommends COVID-19 vaccines for pregnant women and those who are breastfeeding. People who are pregnant or were recently pregnant are at increased risk for a severe outcome from COVID-19. Those who’ve had COVID-19 are also at risk of preterm birth, stillbirth, and possibly other pregnancy complications.

Can my child receive a COVID-19 vaccine?

Children ages 6 months and older now can receive COVID-19 vaccines. The CDC offers detailed information and guidance about vaccines for children and teens.


How do I report adverse reactions to my COVID-19 vaccine?

Adverse reactions should be reported to the Vaccine Adverse Event Reporting System. Reporting is encouraged for any clinically significant adverse event, even if you are unsure if the vaccine is to blame for your issue. Submit a report to VAERS, or call 1-800-822-7967.

Additionally, the CDC developed a new smartphone-based tool, v-safe. It uses text messaging and web surveys for health check-ins following vaccination.

Why should children get vaccinated if they are less likely to become severely ill?

While children tend to have milder illness than adults, some children do get very sick and require hospitalization. Some have long-term health problems, and some die. Additionally, children can spread COVID-19 to vulnerable family members, friends, teachers, and others.

Additionally, children who have underlying medical conditions are more at risk for severe illness than children who do not have such conditions. Children can also develop multisystem inflammatory syndrome (MIS-C), in which different body parts become inflamed, such as the heart, lungs, kidneys, brain, skin, eyes, or gastrointestinal organs.

Can I get a flu vaccine and COVID-19 vaccine at the same time?

Yes. The CDC and other experts say it is fine to receive the COVID-19 vaccine and other vaccines – such as the flu shot – at the same time.

Who should get a COVID-19 booster shot?

To find out whether -- and when -- a booster is recommended for you, use the CDC's tool to assess booster eligibility.

Is it true that people can get a different brand of vaccine for their booster shots than they received for their first shot(s) (two-shot series for Pfizer or Moderna; one shot for Johnson & Johnson)?

Yes, people can now select which vaccines they prefer for their booster shots. Learn more.

How do I schedule a booster shot?

First, try contacting the provider that provided your first shots. If you are having difficulty finding a provider for a booster, visit the CDC’s website for guidance on scheduling your next shot.

Do COVID-19 vaccines have microchips?

No. Read about the ingredients contained in each of the available vaccines.

Will I become magnetic if I get vaccinated?

COVID-19 vaccines do not make people who receive them magnetic. The vaccines do not contain ingredients that can cause an electromagnetic field to develop at the site of injection. Additionally, COVID-19 vaccines do not contain metals.

Will the vaccine change my DNA?

COVID-19 vaccines will not change your DNA. They provide instructions to cells to make a protein that is found in the COVID-19 virus. They never integrate into human DNA.

How long will protection from my COVID vaccines last?

As COVID-19 evolves, so does the science that informs experts how often people in various parts of the world may need to receive additional vaccines. Recent studies show that the protection provided by vaccines may decrease over time. As such, the CDC recommends booster shots following the primary vaccination series. Visit the CDC's website to learn about the timing for all available COVID-19 booster shots.

Should I still get vaccinated if I already had COVID-19? If so, how long should I wait after my recovery?

Yes, experts recommend that you still receive a COVID-19 vaccine following recovery from the virus. While you do get a temporary type of protection called “natural immunity” from having COVID-19, how much protection you have varies.

If you currently have COVID-19, you should wait to be vaccinated until after you finish your isolation period. Also, if you recently had COVID-19, you may -- but do not have to -- consider delaying your next shot (primary dose or booster) by 3 months from when your symptoms started. If you had an asymptomatic infection, you may consider waiting 3 months after your positive test result.