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COVID-19 Vaccine FAQ

Updated June 29, 2022

List of the six facts you need to know about the COVID-19 vaccine.

6 Facts You Need to Know

It is important to understand the facts about COVID-19 vaccine. Providers from Children's Mercy share 6 facts you need to know. 


Frequently asked questions about children and the vaccine

Children can get the vaccine as early as 10 days following a positive test, if they are symptom free.

It is normal to have questions about any new medical treatment or vaccines. The COVID-19 vaccines have gone through the same thorough evaluation, clinical trials and independent reviews as every other vaccine or medication. They were able to go through this cycle and be produced and tested more quickly because the U.S. government, many drug and biotech companies and academic institutions all worked together to develop safe and effective vaccines. The trials to test the vaccine were able to enroll children more quickly than other vaccine trials because many parents and children wanted to participate. Although the process was faster because of these reasons, the vaccines went through the same safety and efficacy evaluation as other vaccines and medications.

Additionally, the vaccine uses messenger RNA (mRNA), a technology which has been around for more than 10 years and has already been used as a cancer treatment. This is not a new type of technology, which is one of the reasons that pharmaceutical companies were able to develop the vaccines quickly.

Based on all we know about the safety of these available vaccines, and all we know about how vaccines in general work to train your own immune system to fight infection, no long-term side effects of the vaccine are expected. The mRNA used in the COVID-19 vaccines only stays in the body for a short period of time before it is broken down.

Kids are getting sick due to COVID-19. Unfortunately, during the delta variant surge, more kids than ever were getting sick from the virus. Although kids are less likely to get really sick or die from COVID-19, many children have required hospitalization and in those who get hospitalized, many end up needing care in the intensive care units and require machines to help them breathe. More kids have died from COVID-19, than the number of kids that die each year from the flu. Also, even kids that get only mild symptoms or no symptoms at all, can still spread the infection to others.

When the vaccines were tested, the most common side effect was pain at the injection site, and it was generally  mild. Other common reactions were fatigue, headaches, muscle pain and chills. Fever was an uncommon side effect. These post-vaccination symptoms are a sign that the body is reacting properly to the vaccine. Essentially, it shows you that your immune system is revving up to protect you. The common side effects seen in children are similar to those seen in adults.

Myocarditis is inflammation of the heart muscle, and pericarditis is inflammation of the outer lining of the heart. In both cases, the body’s immune system causes inflammation in response to an infection or some other trigger. Cases of myocarditis have rarely been reported after mRNA COVID-19 vaccination. Most commonly this occurs in male adolescents and young adults, more often after the second vaccine dose, and usually within the first week after vaccination.

Most patients with myocarditis or pericarditis who received care responded well to medicine and rest and felt better quickly. Patients can usually return to their normal daily activities after their symptoms improve and long-term side effects have not been seen. Myocarditis is much more frequently caused by COVID-19 infection as compared to the vaccine and the benefits of preventing COVID-19 infection in children far outweighs the risk of myocarditis  caused by vaccine. Close monitoring will continue to evaluate cases of adverse effects of the COVID-19 vaccines, including myocarditis.

Yes, everyone who is eligible should still get the vaccine, even if they have already had COVID-19. We know that people can get infected with COVID-19 more than once. In one study, people who had previously had COVID-19 but had not been vaccinated were twice as likely to get COVID-19 again than those who had previously had COVID-19 and been vaccinated.

No. As soon as a child is eligible for the vaccine, they should get it. There is no reason to wait for a child to be 12 to get the vaccine, once the vaccine is authorized for those 5-11 years of age.

On June 20, 6-month-olds through 4-year-olds received emergency authorization to receive the COVID-19 vaccine. This was the final age group to receive authorization, meaning those 6 months and up are now eligible to receive the COVID-19 vaccine. Please talk with your child’s pediatrician to discuss any questions about your child’s eligibility to receive the vaccine.

Yes, a child can get COVID-19 with any other recommended vaccine, including the flu vaccine. It is a great idea to get caught up on all vaccines and the COVID-19 vaccine can be administered with other vaccines.

Talking to people who have already received the COVID-19 vaccine can be helpful to walk friends through what to expect. You can find additional information and resources at The Centers for Disease Control and Prevention also has really helpful information on providing answers to common myths about the vaccine. And the American Academy of Pediatrics has a really helpful parents FAQ website that provides clear facts about the vaccines.

You should always discuss specific vaccine recommendations with your doctor, but the COVID-19 vaccine is recommended for all people who meet eligibility criteria. The only contraindication to the vaccine is previous severe allergic reaction (e.g., anaphylaxis) to a previous vaccine dose or to a vaccine component (e.g., PEG). The vaccine should also not be given for 90 days following treatment with a COVID-19 monoclonal antibody.

The information available about how well the current vaccines from Pfizer, Moderna and Johnson & Johnson protect against new variant COVID-19 strains continues to change as the vaccines are tested against these variant strains and as new variant strains continue to emerge. It appears that the vaccines all provide some protection against the current variant strains, but the protection varies based on the vaccine and the variant strain.

It takes about two weeks after you get the vaccine for you to be protected. For the vaccines that require 2 doses (Pfizer/Moderna), this means that it is two weeks after the second dose. Although there will be some effect two weeks after the first dose, but it won’t be as effective as two weeks after the second dose.

Children’s Mercy is administering the Pfizer vaccine. The doses vary by age group. For those 6 months through four years, they will require three doses. The second dose is given three weeks after the first dose and the third dose is given two months after the second dose. For those 5 years or older two doses are required with the second dose given three weeks after the first dose. It’s important to take all recommended doses of the vaccine.

Children’s Mercy will bill for the cost of giving the vaccine. 

What will happen for those with insurance?

If you have health insurance, you must share that information when you schedule and register for your appointment. We will bill your insurance.

What will happen for those without insurance?

If you do not have insurance, please contact Patient Access Financial Counselors (816) 234-3567.

Who can I call for questions related to COVID vaccine changes?

Children's Mercy Customer Service: (816) 701-5100 or

Health Resources and Administration is a resource for questions about reimbursement for testing, treatment, and vaccines.

On Sept. 16, 2021, we announced a COVID-19 vaccine mandate for all employees, effective Dec. 15, 2021.

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