The companies' findings from Phase 3 trial showed that a two-dose series of their vaccine, 30-microgram per dose, was 100% effective against COVID-19, measured seven days through over four months after the second dose.
The results were based on an analysis of 2,228 participants in the trial, Pfizer said in a statement.
Pfizer Chairman and CEO Albert Bourla said "rates of COVID-19 [are] climbing in this age group in some regions, while vaccine uptake has slowed."
BioNTech CEO and Co-founder Ugur Sahin said the results are "the first and only disclosed longer-term data demonstrating the safety and efficacy of a COVID-19 vaccine in individuals 12 through 15 years of age."
Canada on Thursday approved the Prizer-BioNTech two-dose vaccine for children age 5 to 11.
The Prizer-BioNTech vaccine also received approval in the US on Friday for their COVID-19 booster shots for adults, which will be administered at least six months after completion of the primary series.
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