A Series of Articles on the Science Behind COVID-19
COVID-19 Vaccine for Children
By: Pamela Zeitlin, MD, MPhil, PhD, pediatric pulmonologist, chair of the Department of Pediatrics at National Jewish Health
April 2021
On May 10, 2021, the U.S. Food and Drug Administration expanded the emergency use authorization (EUA) for the Pfizer-BioNTech COVID-19 Vaccine to include adolescents 12 through 15 years of age. The FDA amended the EUA originally issued on Dec. 11, 2020 for administration in individuals 16 years of age and older. See Pfizer Fact Sheet.
On September 22, 2021, the FDA amended the emergency use authorization (EUA) for the Pfizer-BioNTech COVID-19 Vaccine to allow for use of a single booster dose, to be administered at least six months after completion of the primary series in individuals 65 years of age and older; individuals 18 through 64 years of age at high risk of severe COVID-19; and individuals 18 through 64 years of age whose frequent institutional or occupational exposure to SARS-CoV-2 puts them at high risk of serious complications of COVID-19 including severe COVID-19. See Pfizer Fact Sheet.
On October 29, 2021, the FDA authorized emergency use for Pfizer COVID vaccine in children 5-11. Pfizer Fact Sheet ages 5-11 | Pfizer Fact Sheet ages 12+
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Vaccination is in full swing for adults who meet the government’s phased distribution plan. When will children be able to get the vaccine?

Current estimates by Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, indicate that children as young as 6 may be authorized to have certain COVID-19 vaccines in the fall, while older children may be able to get vaccinated this spring.
The vast majority of children who develop COVID-19 have mild or asymptomatic infections, but in both cases they can transmit the disease to others of any age. Because children under the age of 21 make up about 25 percent of the U.S. population, it may be difficult to reach herd immunity until children are fully vaccinated.
Vaccination against COVID-19 in children will protect them and their families from serious infection. Until we can achieve widespread vaccine delivery, families should practice current CDC guidelines for social distancing, hand hygiene and masking based on vaccination status.
Why does it take longer to develop a vaccine for children?
Vaccines are usually developed for adults first to check for safety concerns and then clinical trials are opened up to adolescents, followed by younger children.
The wide range of immune responses from infancy through teenage years can make it challenging for one vaccine to address a disease for all ages. For example, the first time a baby is vaccinated for influenza, a small dose is given, followed by a repeat dose one month later. The Centers for Disease Control and Prevention recommend two doses for children six months through 8 years who have never received the influenza vaccine before. After this first year, these children and older children will only need one annual dose.
Children are considered a vulnerable population, so vaccines developed for them receive special scrutiny. This lengthens the process, while keeping children safe.
Which vaccine makers are conducting clinical trials for children?
Pfizer and Moderna have enrolled children 12 and older in clinical trials of their vaccines and hope to have results by summer. Johnson & Johnson, Novavax and AstraZeneca also plan to test their vaccines in children.
Pfizer BioNTech – shown to prevent symptomatic infection
Emergency Use Authorization (EUA) for this vaccine was expanded by the U.S. Food and Drug Administration (FDA) May 10, 2021 to include adolescents 12 through 15 years of age. This vaccine was originally given EUA by the FDA in December 2020 for anyone 16 and older. On March 31, 2021, Pfizer announced that children 12-17 are 100% protected against COVID-19 infection in a clinical trial. A trial for children under age 12 will require a new study and possibly modified formulation or dosing of the current vaccine before they can finalize their plans to study 5-11 year olds.
Moderna – shown to prevent symptomatic infection
Also, given EUA authorization in December 2020. This vaccine is for people 18 and older. Testing on adolescents ages 12 to 17 began in December, and Moderna expects results midyear. On March 19, 2021 Moderna began testing its COVID-19 vaccine in babies and young children 6 months to 11 years old.
AstraZeneca and Oxford University – early data show it prevents infection and reduces spread
This vaccine has been approved for emergency use in the U.K., but not in the U.S. In February 2021, a new study was launched to assess safety of the vaccine in children 6 to 17. Early data indicate that this vaccine reduces the risk of hospital admissions by 94 percent, and it is less expensive to produce and ship and does not require ultra-cold storage like some other vaccines.
Johnson & Johnson – early data show effectiveness at preventing hospitalization and deaths
This company submitted an application to the FDA and in several other countries for those 18 and older. This single dose vaccine is not an mRNA vaccine but uses disabled genetic material from the common cold virus (adenovirus), so it won’t make people sick or allow the virus to reproduce. Data show that it is 85 percent effective in preventing hospitalization and 100 percent effective in preventing deaths.
Novavax – early data show effectiveness at preventing COVID-19
Recently completed enrolling vaccine study participants in the U.S. and Mexico. Early data from trials in other countries suggest the vaccine is 89 percent effective in preventing COVID-19. The company plans to study the vaccine in children later.
While the COVID-19 vaccine is important, children should receive all their age-appropriate vaccines in the meantime. Check with your child’s doctor about vaccines appropriate for your child.
If you are concerned about the COVID-19 vaccine because your child has severe allergies, asthma, food allergies or other chronic health conditions, remember that complications are rare, and we encourage you to talk with your child’s specialist to determine what’s best for your child’s health needs.