The U.S. Food and Drug Administration ( FDA ) has authorized the emergency use of the Pfizer-BioNTech COVID-19 vaccine for the prevention of COVID-19 to include children 5 through 11 years of age.
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.
The Pfizer-BioNTech COVID-19 vaccine for children 5 through 11 years of age is administered as a two-dose primary series, 3 weeks apart, but is a lower dose ( 10 micrograms ) than that used for individuals 12 years of age and older ( 30 micrograms ).
In the U.S., COVID-19 cases in children 5 through 11 years of age make up 39% of cases in individuals younger than 18 years of age.
According to the CDC, approximately 8,300 COVID-19 cases in children 5 through 11 years of age resulted in hospitalization. As of Oct. 17, 691 deaths from COVID-19 have been reported in the U.S. in individuals less than 18 years of age, with 146 deaths in the 5 through 11 years age group.
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 down to 5 years of age outweigh the known and potential risks.
FDA evaluation of available effectiveness data
The effectiveness data to support the EUA in children down to 5 years of age is based on an ongoing randomized, placebo-controlled study that has enrolled approximately 4,700 children 5 through 11 years of age.
The study is being conducted in the U.S., Finland, Poland and Spain. Children in the vaccine group received two doses of the Pfizer-BioNTech COVID-19 vaccine containing 10 micrograms of messenger RNA per dose.
The FDA analyzed data that compared the immune response of 264 participants from this study to 253 participants 16 through 25 years of age 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 age participants were comparable to the older participants.
The FDA has also conducted a preliminary analysis of cases of COVID-19 occurring seven days after the second dose.
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 ) ages 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, 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 two days after vaccination, and most went away within one to two days.
The FDA and CDC safety surveillance systems have previously identified increased risks of myocarditis ( inflammation of the heart muscle ) and pericarditis ( inflammation of tissue surrounding the heart ) following vaccination with Pfizer-BioNTech COVID-19 vaccine, particularly following the second dose, and with the observed risk highest in males 12 through 17 years of age.
Therefore, the FDA has 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 in children 5 through 11 years of age would prevent versus 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 5 through 11 years of age.
New vaccine formulation
The FDA has 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 has 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. ( Xagena )
Source: FDA, 2021