3 small-dose COVID vaccine for children 6 mos-5 yrs from Pfizer/BioNTech

Pfizer and BioNTech today announced topline safety, immunogenicity and vaccine efficacy data from a Phase 2/3 trial evaluating a third 3-µg dose of the Pfizer-BioNTech COVID-19 Vaccine in children 6 months to under 5 years of age. Following a third dose in this age group, the vaccine was found to elicit a strong immune response, with a favorable safety profile similar to placebo.

Vaccine efficacy, a secondary endpoint in this trial, was 80.3% in children 6 months to under 5 years of age. This descriptive analysis was based on 10 symptomatic COVID-19 cases identified from seven days after the third dose and accrued as of April 29, 2022. The trial protocol specifies a formal analysis will be performed when at least 21 cases have accrued from seven days after the third dose. Final vaccine efficacy data will be shared once available.

“Our COVID-19 vaccine has been studied in thousands of children and adolescents, and we are pleased that our formulation for the youngest children, which we carefully selected to be one-tenth of the dose strength for adults, was well-tolerated and produced a strong immune response,” said Albert Bourla, Chairman and Chief Executive Officer, Pfizer. “These topline safety, immunogenicity and efficacy data are encouraging, and we look forward to soon completing our submissions to regulators globally with the hope of making this vaccine available to younger children as quickly as possible, subject to regulatory authorization.”

“The study suggests that a low 3-ug dose of our vaccine, carefully selected based on tolerability data, provides young children with a high level of protection against the recent COVID-19 strains,” said Prof. Ugur Sahin, M.D., CEO and co-founder of BioNTech. “We are preparing the relevant documents and expect completing the submission process to the FDA this week, with submissions to EMA and other regulatory agencies to follow within the coming weeks.”

In the Phase 2/3 trial, 1,678 children received a third dose of the 3-µg formulation at least two months after the second dose at a time when Omicron was the predominant variant. The immunogenicity analysis of geometric mean titer (GMT) ratio and seroresponse rate was conducted on a subset of study participants one month following the third dose in children 6 months to under 5 years of age, compared to the second dose in the 16- to 25-year-old population. Non-inferiority was met for both the 6- to 24-month-old population and the 2- to under 5-year-old population for both co-primary endpoints. Three 3-µg doses of the Pfizer-BioNTech COVID-19 Vaccine was well-tolerated in this age group, and no new safety signals were identified. The majority of adverse events were mild or moderate.

Studies in adults, adolescents, and children over 5 years of age continue to indicate that three doses of the Pfizer-BioNTech COVID-19 Vaccine enhance protection compared to two doses. The safety, immunogenicity and vaccine efficacy data for three doses of the vaccine in children under 5 years of age are consistent with the data seen in adults, suggesting that a third dose will provide similar benefit in children.

In February 2022, the companies initiated a rolling submission for Emergency Use Authorization (EUA) of their COVID-19 vaccine in children 6 months to under 5 years of age, following a request by the U.S. Food and Drug Administration (FDA). At that time, a two-dose series was determined to be well-tolerated in this age group. Pfizer and BioNTech plan to submit these new safety, immunogenicity, and vaccine efficacy data on three doses to the rolling U.S. EUA application this week, with submissions to regulators worldwide to follow.

The Pfizer-BioNTech COVID-19 Vaccine, which is based on BioNTech’s proprietary mRNA technology, was developed by both BioNTech and Pfizer. BioNTech is the Marketing Authorization Holder in the United States, the European Union, the United Kingdom, Canada and the holder of emergency use authorizations or equivalents in the United States (jointly with Pfizer) and other countries. Submissions to pursue regulatory approvals in those countries where emergency use authorizations or equivalent were initially granted are planned.

About the Phase 1/2/3 Trial in Children
The Phase 1/2/3 trial has enrolled more than 10,000 children ages 6 months to under 12 years of age in the United States, Finland, Poland, and Spain from more than 90 clinical trial sites. The trial evaluated the safety, tolerability, and immunogenicity of three doses of the Pfizer-BioNTech COVID-19 Vaccine in three age groups: ages 5 to under 12 years; ages 2 to under 5 years; and ages 6 months to under 2 years. Based on the Phase 1 dose-escalation portion of the trial, children ages 5 to under 12 years received a two-dose schedule of 10 µg each while children under age 5 received a lower 3 µg dose for each injection in the Phase 2/3 study. The trial enrolled children with or without prior evidence of SARS-CoV-2 infection.

U.S. Indication & Authorized Use
Pfizer-BioNTech COVID-19 Vaccine is FDA authorized under Emergency Use Authorization (EUA) for active immunization to prevent coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in individuals 5 years of age and older.
Pfizer-BioNTech COVID-19 Vaccine is FDA authorized to provide:

Primary Series

• a 2-dose primary series to individuals 5 years of age and older
• a third primary series dose to individuals 5 years of age and older with certain kinds of immunocompromise

Booster Series

• a single booster dose to individuals 5 through 11 years of age who have completed a primary series with Pfizer-BioNTech COVID-19 Vaccine
• a first booster dose to individuals 12 years of age and older who have completed a primary series with Pfizer-BioNTech COVID-19 Vaccine or COMIRNATY^® (COVID-19 Vaccine, mRNA)
• a first booster dose to individuals 18 years of age and older who have completed primary vaccination with a different authorized or approved COVID-19 vaccine. The booster schedule is based on the labeling information of the vaccine used for the primary series
• a second booster dose to individuals 50 years of age and older who have received a first booster dose of any authorized or approved COVID-19 vaccine
• a second booster dose to individuals 12 years of age and older with certain kinds of immunocompromise and who have received a first booster dose of any authorized or approved COVID-19 vaccine

CDC Strengthens Recommendations and Expands Eligibility for COVID-19 Booster Shots

CDC has expanded eligibility of COVID-19 vaccine booster doses to everyone 5 years of age and older, recommending that children ages 5 through 11 years should receive a booster shot 5 months after their initial Pfizer-BioNTech vaccination series.

Vaccination with a primary series among this age group has lagged behind other age groups leaving them vulnerable to serious illness.

CDC has also strengthened its recommendation that those 12 and older who are immunocompromised and those 50 and older should receive a second booster dose at least 4 months after their first.

While older Americans have the highest coverage of any age group of first booster doses, most older Americans received their last dose many months ago, leaving many who are vulnerable without the protection they may need to prevent severe disease, hospitalization, and death.