Moderna has said its Covid-19 vaccine strongly protects children as young as 12, a step that could put the jab on track to become the second option for that age group in the US

With global vaccine supplies still tight, much of the world is struggling to vaccinate adults in the quest to end the pandemic.

Earlier this month, the US and Canada authorised another vaccine — the shot made by Pfizer and BioNTech — to be used starting at age 12.

Moderna aims to be next in line, saying it will submit its teen data to the US Food and Drug Administration and other global regulators early next month.

The company studied more than 3,700 12 to 17-year-olds. Preliminary findings showed the vaccine triggered the same signs of immune protection in children as it does in adults, and the same kind of temporary side effects such as sore arms, headache and fatigue.

There were no Covid-19 diagnoses in those given two doses of the Moderna vaccine compared with four cases among children given dummy injections.

In a press release, the company also said the vaccine appeared to be 93% effective two weeks after the first dose.

While children are far less likely than adults to get seriously ill with Covid-19, they represent about 14% of the nation’s coronavirus cases. At least 316 have died in the US alone, according to a tally by the American Academy of Pediatrics.

With plenty of vaccine supply in the US, younger teens flocked to get Pfizer’s vaccine in the days after FDA opened it to them, part of a push to get as many children vaccinated as possible before the next school year.

Both Pfizer and Moderna have begun testing in even younger children, from age 11 down to six-month-old babies.

This testing is more complex: teenagers receive the same dose as adults, but researchers are testing smaller doses in younger children. Experts hope to see some results in the autumn.