Canada became the first country to approve a coronavirus vaccine for use in children under the age of 16, as it authorised the BioNTech/Pfizer jab for 12 to 15-year-olds.

The country’s health department said the decision announced on Wednesday was based on data from phase 3 trials that showed 100 per cent efficacy in the prevention of symptomatic Covid-19 in that age group.

“After completing a thorough and independent scientific review of the evidence, the department has determined that this vaccine is safe and effective at preventing Covid-19 when used in children between 12 and 15 years of age,” Health Canada said.

The BioNTech/Pfizer vaccine is the only one given to people aged 16-17 but this would be the first authorisation for younger children. The Moderna, Oxford/AstraZeneca and Johnson & Johnson jabs are currently restricted to individuals aged 18 and over.

In the US, nearly 2m under-18s have received at least one vaccine dose, according to figures from the Centers for Disease Control and Prevention. US regulators are considering whether to approve the BioNTech/Pfizer jab for younger people, with an announcement expected in the coming days. The drugmakers have also applied to the European health regulator.

More than 1bn does of coronavirus vaccine have been administered around the world, with the overwhelming majority given to adults.

Some have questioned the ethics of vaccinating children in wealthy countries, who are much less likely to die from the virus than older cohorts, while vast swaths of the adult population globally have yet to be immunised.

Nine under-20s have died from coronavirus in Canada to the end of April, according to government figures, compared with 16,195 aged over 80. In the US, just over 300 under-18s have died from Covid-19 since the pandemic began, compared with more than 550,000 adults, according to the CDC

“[It is] reasonable to say we are going to immunise children so that we are going to protect the rest of society, but ethically there has to be a benefit for the individual themselves,” said James Conway, a paediatric infectious disease specialist at the University of Wisconsin-Madison.

Others say children should be vaccinated to stop transmission of the virus to adults, which will help societies reach herd immunity and return to normal.

“Just because 500,000 children haven’t died doesn’t mean it’s not important to consider this as a disease in kids. We don’t want to see any child die or get hospitalised,” said Yvonne Maldonado, a Stanford university professor who leads trials of the BioNTech/Pfizer vaccine on toddlers aged two to five.

Fabien Paquette, vaccines lead at Pfizer Canada, said the regulatory approval represented “a significant step forward in helping the Canadian government broaden its vaccination programme and begin to help protect adolescents before the start of the next school year”.

The western pharmaceutical companies that produce coronavirus vaccines are at various stages of carrying out trials of their shots on children, some as young as six months, although Pfizer and BioNTech are the only ones to have submitted data. Moderna is preparing to submit its data to US authorities following trials on 12 to 17-year-olds.