On October 29, the U.S. Food and Drug Administration (FDA) authorized the emergency use of the Pfizer-BioNTech COVID-19 vaccine for the prevention of COVID-19 to include children aged 5 through 11 years. The authorization was based on the FDA’s thorough and transparent evaluation of the data that included input from independent advisory committee experts who overwhelmingly voted in favor of making the vaccine available to children in this age group.
Key points for parents and caregivers include:
- Effectiveness: Immune responses of children aged 5 through 11 years were comparable to those of individuals aged 16 through 25. In addition, the vaccine was found to be 90.7% effective in preventing COVID-19 in children 5 through 11.
- Safety: The vaccine’s safety was studied in approximately 3,100 children aged 5 through 11 years who received the vaccine, and no serious side effects have been detected in the ongoing study.
- The Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices will meet next week to discuss further clinical recommendations.
“As a mother and a physician, I know that parents, caregivers, school staff, and children have been waiting for [this] authorization. Vaccinating younger children against COVID-19 will bring us closer to returning to a sense of normalcy,” said Acting FDA Commissioner Janet Woodcock, MD. “Our comprehensive and rigorous evaluation of the data pertaining to the vaccine’s safety and effectiveness should help assure parents and guardians that this vaccine meets our high standards.”
The Pfizer-BioNTech COVID-19 Vaccine for children aged 5 through 11 years is administered as a two-dose primary series, 3 weeks apart, but is a lower dose (10 µg) than that used for individuals aged 12 years and older (30 µg).
In the United States, COVID-19 cases in children aged 5 through 11 years make up 39% of cases in individuals younger than age 18. According to the CDC, approximately 8,300 COVID-19 cases in children aged 5 through 11 years resulted in hospitalization. As of October 17, 2021, 691 deaths from COVID-19 have been reported in the United States in individuals younger than age 18 years, with 146 deaths recorded in children aged 5 through 11 years.
“The FDA is committed to making decisions that are guided by science that the public and health-care community can trust. We are confident in the safety, effectiveness, and manufacturing data behind this authorization. As part of our commitment to transparency around our decision-making, which included our public advisory committee meeting earlier this week, we have posted documents supporting our decision, and additional information detailing our evaluation of the data will be posted soon. We hope this information helps build confidence of parents who are deciding whether to have their children vaccinated,” said Peter Marks, MD, PhD, Director of the FDA’s Center for Biologics Evaluation and Research.
The FDA has determined this Pfizer vaccine has met the criteria for emergency use authorization. Based on the totality of scientific evidence available, the known and potential benefits of the Pfizer-BioNTech COVID-19 vaccine in individuals aged 5 through 11 years outweigh the known and potential risks.
FDA Evaluation of Available Effectiveness Data
The effectiveness data to support the emergency use authorization (EUA) in children aged 5 through 11 years is based on an ongoing randomized, placebo-controlled study that has enrolled approximately 4,700 children in this age bracket. The study is being conducted in the United States, Finland, Poland, and Spain. Children in the vaccine group received two doses of the Pfizer-BioNTech COVID-19 vaccine containing 10 µg of messenger RNA per dose.
The FDA analyzed data that compared the immune response of 264 participants from this study to 253 participants aged 16 through 25 years who had two higher doses of the vaccine in a previous study which determined the vaccine to be effective in preventing COVID-19. The immune responses of the younger participants were comparable to the older participants.
The FDA also conducted a preliminary analysis of cases of COVID-19 occurring 7 days after the second dose of the vaccine. In this analysis, among participants without evidence of prior infection with SARS–CoV-2, 3 cases of COVID-19 occurred among 1,305 vaccine recipients and 16 cases of COVID-19 occurred among 663 placebo recipients; the vaccine was 90.7% effective in preventing COVID-19.
FDA Evaluation of Available Safety Data
The available safety data to support the EUA include more than 4,600 participants (3,100 vaccine, 1,538 placebo) aged 5 through 11 years enrolled in the ongoing study. In this trial, a total of 1,444 vaccine recipients were followed for safety for at least 2 months after the second dose.
Commonly reported side effects in the clinical trial included injection site pain (sore arm), redness and swelling, fatigue, headache, muscle and/or joint pain, chills, fever, swollen lymph nodes, nausea, and decreased appetite. More children reported side effects after the second dose than after the first dose. Side effects were generally mild to moderate in severity and occurred within 2 days after vaccination; most went away within 1 to 2 days.
The FDA and CDC safety surveillance systems have previously identified increased risks of myocarditis and pericarditis following vaccination with Pfizer-BioNTech COVID-19 vaccine, particularly following the second dose, and with the observed risk highest in males aged 12 through 17 years. Therefore, the FDA conducted its own benefit-risk assessment using modelling to predict how many symptomatic COVID-19 cases, hospitalizations, intensive care unit (ICU) admissions, and deaths from COVID-19 the vaccine would prevent in children aged 5 through 11 years vs the number of potential myocarditis cases, hospitalizations, ICU admissions, and deaths that the vaccine might cause. The FDA’s model predicts that, overall, the benefits of the vaccine would outweigh its risks in children aged 5 through 11 years.
Ongoing Safety Monitoring
Pfizer has updated its safety monitoring plan to include evaluation of myocarditis, pericarditis, and other events of interest in children aged 5 through 11 years. In addition, the FDA and the CDC have several systems in place to continually monitor COVID-19 vaccine safety and allow for the rapid detection and investigation of potential safety problems.
It is mandatory for Pfizer and vaccination providers to report to any serious adverse events, cases of multisystem inflammatory syndrome, and cases of COVID-19 that result in hospitalization or death in vaccinated individuals. It is also mandatory for vaccination providers to report all vaccine administration errors to the Vaccine Adverse Event Reporting System for which they become aware and for Pfizer to include a summary and analysis of all identified vaccine administration errors in monthly safety reports to the FDA.
Data Supports New Vaccine Formulation to Improve Stability and Storage Conditions
The FDA also authorized a manufacturing change for the vaccine to include a formulation that uses a different buffer; buffers help maintain a vaccine’s pH and stability. This new formulation is more stable at refrigerated temperatures for longer periods of time, permitting greater flexibility for vaccination providers.
The new formulation of the vaccine developed by Pfizer contains Tris buffer, a commonly used buffer in a variety of other FDA-approved vaccines and other biologics, including products for use in children. The FDA evaluated manufacturing data to support the use of Pfizer-BioNTech COVID-19 vaccine containing Tris buffer and concluded it does not present safety or effectiveness concerns.
