Three doses of the Pfizer-BioNTech COVID-19 vaccine were roughly 80 percent effective at preventing infections for children ages 6 months to 5 years old, according to trial data Pfizer released Monday.
Nearly 1,700 children received a third vaccine dose at least two months after their second as part of the trial. An analysis of immune responses to the virus in a subset of the children in the study found their vaccine-driven immune response was similar to that of the second vaccine dose among people ages 16-25.
According to Pfizer and BioNTech, the third vaccine dose was 80.3 percent effective even during surges of newer COVID variants like omicron that have proven more infectious than initial strains of the virus.
"The study suggests that a low ... 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 BioNTech CEO and Co-Founder Dr. Ugur Sahin.
Pfizer and BioNTech officials submitted their initial data to federal regulators in February showing the efficacy and safety of the COVID vaccine in children under age 5.
That initial data was focused on a two-dose initial vaccination series, according to Pfizer. Following Monday's announcement of a third dose being effective, the two companies plan to submit the latest data to the U.S. Food and Drug Administration this week.
FDA officials have tentatively planned to consider vaccine safety and efficacy data for children under 5 from both Pfizer-BioNTech and the Massachusetts-based biotechnology company Moderna in mid-June.
The Pfizer-BioNTech vaccine is approved under an Emergency Use Authorization for everyone ages 5-15 and fully approved and marketed as Comirnaty for everyone ages 16 and up.
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