The companies expect vaccination of this age group to begin before the next school year.
Phase 3 trials conducted in 2,260 adolescents in the United States "demonstrated 100 percent efficacy and robust antibody responses," the companies said in a statement.
US-based Pfizer and German BioNTech will now submit this data to the different regulatory authorities in the world "in the hope of starting to vaccinate this age group at the beginning of the next school year," Albert Bourla, CEO of the US pharmaceutical giant, said in a statement.
For the German laboratory, Ugur Sahin, considered that the results about the 12-15 years old group are "very encouraging, given the trend observed in recent weeks regarding the spread" of the virus variant initially detected in the UK.
Pfizer/BioNTech's vaccine, based on innovative messenger RNA (mRNA) technology, was the first against Covid-19 approved in the West in late 2020.
The United States and the European Union have authorised use for people aged 16 and over.
So far, the vaccine has been used in millions of adults over the age of 65.
A real-world study in 1.2 million people in Israel showed 94 percent efficacy.
Children are less prone to severe cases of the disease, which is why vaccination is not a priority at this time.