COVID-19 Vaccine Safety for Kids—What You Need to Know, According to an Expert

girl getting vaccine

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As of December 2022, the FDA has approved updated bivalent booster shots for everyone ages 6 months and up. These boosters help protect against both the original strain of COVID-19 and the Omicron variant, and are safe, effective, and recommended by the CDC.

For kids 4 and under, booster eligibility depends on which shot they got for their primary series (Pfizer or Moderna) and when. Kids 5 and up can get a Pfizer booster as long as it has been two months since their last shot or booster. Kids 6 and up can get either a Pfizer or a Moderna booster two months after their previous shot.

Key Takeaways

  • The Pfizer COVID-19 vaccine has been approved for children aged 5 to 11 and millions have received their first dose safely.
  • Children receive a smaller dose of the vaccine, and are encouraged to get a second dose three weeks later, just like adults.
  • The vaccine has been tested in trials, and has been proven to be safe and effective. 

Chances are that if your child is between 5 and 11 years old, you have been frenetically watching the news and waiting for the approval of the COVID-19 vaccine in children. However, now that the Pfizer vaccine has been approved for emergency authorization, many parents have a host of questions they want to be answered before bringing their child for their shot.

As of November 17, the White House says that 2.6 million children aged 5 to 11 have received the vaccine, which is 10% of the total population of that age group living in the United States.

We spoke with an expert—Sara Siddiqui MD, FAAP, who specializes in pediatric and adolescent medicine at NYU Langone Huntington Medical Group in New York—to help separate fact from fiction.

Dr. Siddiqui, a board-certified physician, treats children from birth to 21 years old and has been practicing for nearly 20 years. Dr. Siddiqui dispels myths about the vaccine, explains the risks, and describes the dosage kids will receive.

How did the FDA determine the effectiveness and safety for children 5 to 11 years old to receive the COVID-19 vaccine? 

Dr. Siddiqui: The FDA uses rigorous standards to determine and, ultimately, approve vaccines for administration. They use strict criteria to ensure safety and efficacy. These standards have been maintained in the approval process for the COVID-19 vaccines. The timeline was able to be improved as the meeting process was moved up—not the actual studies performed. 

How long have these vaccines been in trials? Have there been any long-term effects in kids? 

Dr. Siddiqui: Pediatric COVID-19 vaccine trials began as early as June 2020. The Pfizer trial included approximately 4,600 children (3,100 who got the vaccine, 1,500 who got a placebo) and showed a 91% effectiveness against contracting COVID-19. In the pediatric trial for ages 5 to 11 years old, side effects included arm pain and redness at the vaccination site, and fever. Long-term effects for all vaccines currently approved usually occur in the first six to nine months of the administration. The pediatric COVID-19 vaccine was done over a period of 18 months. 

What is the dosing size and do kids need two shots spaced out like adults?

Dr. Siddiqui: The current recommendation for the Pfizer pediatric vaccine ages 5 to 11 years is a 10mcg [microgram] dosing requiring two doses taken three weeks apart. Full vaccination effect is considered two weeks after the second dose. Side effects such as arm pain and redness usually occur within the first 48 hours of administration. [Adult COVID-19 vaccines are 30 micrograms.]

What are the most common side effects for kids after getting the vaccine? 

Dr. Siddiqui: The most common side effects for ages 5 to 11 years of age were arm pain, redness, and/or swelling at the injection site. Other side effects include tiredness, headache, muscle pain, chills, fever, and nausea. This is typical with many other vaccines as well.

What medications can/should I give my child after the shot to ease the pain? 

Dr. Siddiqui: You may wish to administer acetaminophen or ibuprofen to a child experiencing side effects after vaccination. Placing a cool damp cloth at the site will help as well. Please discuss dosing and frequency of non-aspirin medications with your pediatrician or childcare provider. 

What is myocarditis? How high is the risk? 

Dr. Siddiqui: Myocarditis is an accumulation of fluid and swelling around the heart muscle and can occur after some viral infections. It is a rare side effect reported after COVID-19 vaccination in children ages 12 and up. Myocarditis and pericarditis can be a result of COVID-19 infection as well and is a rare occurrence in children. Side effects after vaccination resulting in myocarditis are much less severe than those reported after COVID-19 infection in children.

Also, myocarditis reported after vaccination was treated with ibuprofen, and those children recovered quickly with less severe symptoms. Please contact your child's healthcare provider if your child experiences chest pain, shortness of breath, extreme fatigue, or rapid heart rate after receiving the first or second COVID-19 vaccination. 

In the pediatric COVID-19 vaccine trial for ages 5 to 11, there were NO reported cases of myocarditis. It is thought the decrease in dosing may have helped with the reduction in the side effects. The pediatric COVID-19 vaccine approved for ages 5 to 11 is one-third of the dose of the 12+ Pfizer COVID-19 vaccine. 

Why do vaccine requirements vary by age? 

Dr. Siddiqui: During the initial trial phase, dosing requirements varied with age as the immune system may function differently in children than adults. Trials for ages 6 months and up are also currently ongoing, with even more of a reduction in dosing being given. 

Can my child get the COVID 19 vaccine at the same time as their flu shot? 

Dr. Siddiqui: The current recommendation by the CDC and Advisory Committee on Immunization Practices (ACIP) is that, yes, both can be given at the same time.

When do you expect the vaccine to be available for children under 5? 

Dr. Siddiqui: Current pediatric trials for COVID-19 vaccination in ages 6 months and above are underway. Hopefully, we will be seeing the results of that data soon.

Can my child get a breakthrough case of COVID-19 after vaccination like some adults have? Will it lessen the severity? 

Dr. Siddiqui: COVID-19 vaccination greatly reduces the risk of severe disease and hospitalization. There may be a chance of breakthrough cases even for those vaccinated; however, the risk of severe illness and mortality has been shown to be significantly reduced. 

There have been rumors this vaccine will affect future fertility or menstrual cycles in our children. Does the COVID-19 vaccine impact fertility?

Dr. Siddiqui: Unfortunately, misinformation regarding fertility and the COVID-19 vaccine has spread. The American College of Obstetricians and Gynecologists has put out multiple statements regarding the safety and efficacy of the COVID vaccine in all women, including during pregnancy and lactation.

The current mRNA vaccine does not change the DNA of the cells, nor does it travel within the nucleus of the cell where the DNA is present. The mRNA vaccine simply gives cells a map to produce the spike protein by cells, then the cells produce antibodies against the spike protein. The actual mRNA is destroyed soon after and does not stay in the system. The mRNA vaccine does not impact fertility in males or females.

Should kids still wear masks if they are vaccinated? 

Dr. Siddiqui: Until a significant number of the population has been vaccinated, and COVID-19 case counts, hospitalizations, morbidity, and mortality have been shown to be reduced, we may need to continue mitigation strategies when in indoor crowded areas, especially in the winter. This would include getting vaccinated if eligible, masking, distancing, and testing when sick. Hopefully, soon, we will be one step closer to returning to normal.

What This Means For You

If you have a child between the ages of 5 and 11, it’s important to get them vaccinated as soon as possible. The vaccine has been proven to be safe and effective for this age group. Getting your child vaccinated will help stop the spread of the virus during the holiday season and winter months, and beyond. Be sure to talk to your child's healthcare provider if you have additional questions.

10 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Stay up to date with COVID-19 vaccines including boosters.

  2. U.S. Food and Drug Administration. Coronavirus (COVID-19) update: FDA authorizes updated (bivalent) COVID-19 vaccine for children down to 6 months of age.

  3. The White House. Press briefing by White House COVID-⁠19 Response Team and public health officials.

  4. Centers for Disease Control and Prevention. Developing COVID-19 vaccines.

  5. U. S. Food and Drug Administration. FDA authorizes Pfizer-BioNTech COVID-19 vaccine for emergency use in children 5 through 11 years of age.

  6. Centers for Disease Control and Prevention. COVID-19 vaccines for children and teens.

  7. Centers for Disease Control and Prevention. Interim clinical considerations for use of COVID-19 vaccines currently approved or authorized in the United States.

  8. Marshall M, Ferguson ID, Lewis P, et al. Symptomatic acute myocarditis in 7 adolescents after Pfizer-BioNTech COVID-19 vaccination. Pediatrics. 2021;148(3):e2021052478. doi:10.1542/peds.2021-052478

  9. American College of Obstetricians and Gynecologists. ACOG and SMFM recommend COVID-19 vaccination for pregnant individuals.

  10. Centers for Disease Control and Prevention. Understanding mRNA COVID-19 vaccines.

By Dory Zayas
Dory Zayas is a freelance beauty, fashion, and parenting writer. She spent over a decade writing for celebrity publications and since having her daughter in 2019, has been published on sites including INSIDER and Well+Good.