Moderna will seek approval from EU regulators to supply its Covid-19 vaccine to children as young as 12.
The shot is currently available for over-18s in Europe, but Moderna said it was 96 per cent effective among children aged 12 to 17.
Pfizer's vaccine was this month approved for children in the US but its application in Europe has yet to be ruled on by the European Medicines Agency (EMA).
Moderna chief executive Stephane Bancel told French newspaper Le Journal Du Dimanche that the company would submit its own application to the EMA next month.
The ideal outcome would be for children in countries such as France to be vaccinated by August, he said.
“If we do not vaccinate massively, the risk of a fourth wave cannot be shifted aside,” he said.
The Moderna trial results showed 96 per cent efficacy in a study involving more than 3,200 youngsters.
There were no serious side effects, although some children suffered headaches, chills and fatigue after their second dose.
Moderna is running a separate trial for children between six months and 12 years.
Participants in that trial were given their first doses in March. Results are yet to be reported.
The head of the World Health Organisation said wealthy countries should donate spare doses to the global Covax scheme instead of giving them to children.
“I understand why some countries want to vaccinate their children and adolescents, but right now I urge them to reconsider and to instead donate vaccines to Covax,” said Dr Tedros Adhanom Ghebreyesus, director general of the WHO.
His comments came after Pfizer’s vaccine was approved for children aged 12 to 15 by the US Food and Drug Administration.
The EMA says it expects to make a decision in June on giving Pfizer shots to children in Europe.
Pfizer’s vaccine is currently available for over-16s in Europe, while the Moderna, Johnson & Johnson and AstraZeneca shots were approved for over-18s.
AstraZeneca is carrying out its own trial for children aged between six and 17.
Under the EU's plans for a digital travel certificate, children who have not yet been vaccinated will have to show a negative result from a PCR test.
EU leaders say the certificate is on track to be introduced by the end of June after an agreement between the European Council and Parliament on Friday.
Member states will be obliged to accept EMA-approved vaccines and may accept others such as Russia’s Sputnik V shot.