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How Is the Vaccine Given?

Vaccines made by Pfizer/BioNTech, Moderna, and Novavax are given via two shots. The first dose starts building protection against the virus and the second dose gives you the most protection. Both doses are needed to fully protect you from getting sick with COVID-19. The Janssen (a Johnson & Johnson company) vaccine only requires one dose for full protection. Three shots of the Pfizer/BioNTech vaccine are required for children 6 months of age to 4 years old.

If you're moderately or severely immunocompromised (see CDC list for qualifying medical conditions), you will need a third dose of the mRNA vaccines or an additional dose of the Janssen vaccine to be considered fully vaccinated. View the CDC's COVID-19 vaccine recommendations for immunocompromised individuals.


When does my child have to receive the second dose?

People ages 6 years and older who are unvaccinated, or previously received only vaccine dose, are recommended to receive one updated mRNA vaccine dose. 

For children 6 months of age to 5 years old, the number of doses they receive will depend on whether they receive the Pfizer/BioNTech or Moderna vaccine and their vaccination history. Pfizer/BioNTech and Novavax doses are given 3-8 weeks apart and Moderna doses are given 4-8 weeks apart. The second or third doses should be administered as close to the recommended time frames as possible. 

What if my child can’t receive the second dose within the recommended time frame?

Testing has shown that the second dose is just as effective when given up to 42 days after the first dose. However, it is still best to get your child their second dose within the recommended time frame. According to the Centers for Disease Control and Prevention (CDC), even second doses given four days earlier than the recommended date are still considered effective.

Can my child mix vaccines for the first and second doses?

This is not recommended. Both doses your child receives need to be manufactured by the same company. At this time, we do not know whether combining vaccines by various manufacturers will give your child the same protection against COVID-19.

How long does vaccine immunity take?

The full immune response appears to be reached two weeks after the final dose of Pfizer/BioNTech, Moderna, and Novavax vaccines. The Johnson & Johnson vaccine takes about four weeks for full protection against COVID-19.

Vaccine Considerations for Specific Groups of People

Can my child or teen get the vaccine?

At this time, both vaccines made by Pfizer/BioNTech and Moderna have been authorized for use in people 6 months of age and older. However, the Janssen (Johnson & Johnson) vaccine has only been authorized for use in people ages 18 and older and the Novavax vaccine has only been authorized for emergency use in people ages 12 and older.

I'm pregnant. Will the vaccine harm me or my baby?

Getting infected with COVID-19 while you're pregnant puts you at an increased risk of developing severe illness, having a premature birth or stillborn birth, and pregnancy complications. People who are pregnant or lactating (producing breast milk) can currently receive any of the FDA-authorized COVID-19 vaccines.

No safety concerns have been seen in vaccinated people who are pregnant or breastfeeding and their babies. In fact, vaccination is likely beneficial since COVID-19 antibodies are passed through breast milk and can protect the baby from COVID-19 after birth. Health care experts say that the benefits of getting vaccinated far outweigh any potential risk with the vaccines.

If you are pregnant, lactating, or in the postpartum stage and under the age of 50, there is a rare risk of developing TTS after getting the Johnson & Johnson vaccine. However, there are other COVID-19 vaccines available to you that do not carry this same risk. Talk to your health care provider first if you have questions about the vaccine or choosing the right one for you.

I'm over the age of 65. Is the vaccine safe for me? 

The current CDC recommendations are to vaccinate all adults (regardless of other risks) age 65 and older. The most recent data from clinical trials shows that the vaccine was very effective (better than 90 percent) in protecting people 65 years and older. The rate of harmful reactions in older adults has also been low — likely lower than the flu vaccine. At this time, there is not a lot of information on adults who are 90 years of age and older. If you have questions about the vaccine, consult with your doctor.

If You Currently Have COVID-19

Can I still get the vaccine if I am experiencing COVID-19 symptoms?

If you have COVID-19 symptoms and have not been vaccinated yet, isolate yourself and get tested immediately. You may be vaccinated after you have recovered from COVID-19 and your isolation period is over. COVID-19 vaccines do not interfere with the results of a COVID-19 test. 

What if I get COVID-19 in between doses?

If you tested positive for COVID-19 after your first dose of the Pfizer/BioNTech, Moderna, or Novavax vaccine, you must:

  • wait until you are finished isolating (at least five days for people with or without symptoms) and
  • wait until your symptoms improve and are fever-free for 24 hours without the use of medication before your second dose.

It doesn’t matter if you’ve been infected with COVID-19 before, clinical data shows that the Pfizer/BioNTech, Moderna, and Novavax vaccines only provide complete protection from COVID-19 after two doses. People with long-term COVID-19 symptoms should talk to their doctor before getting vaccinated. 

Exposed to COVID-19 After Vaccination

I was exposed to someone who tested positive with COVID-19. Do I need to quarantine if I’m fully vaccinated?

COVID-19 vaccines strongly protect against severe illness and death, but it's still possible to develop a milder illness even if you're fully vaccinated and boosted. You'll have the strongest protection against the virus when it's been two weeks since:

  • you received your final dose of the Pfizer/BioNTech, Moderna, or Novavax vaccine,
  • you received a single dose of the Janssen (Johnson & Johnson) vaccine, or
  • booster dose. 

However, you should get tested at least five days after the date of exposure. Even if you test negative, you should still wear a mask in public indoor settings and at home for 10 days after the date of exposure. 

If you experience symptoms of COVID-19 after you were exposed or test positive for COVID-19, call your health care provider and isolate at home from others.

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