Moderna will file COVID-19 jab for teens after trial shows 100% protection

Moderna's COVID-19 vaccine has joined the Pfizer/BioNTech jab in showing efficacy in younger patients in clinical trials, setting up an emergency use filing early next month.

The results of the phase 2/3 TeenCOVE study in more than 3,700 adolescents aged 12 to 17 revealed no cases of COVID-19 after two doses of the mRNA-1273 shot, giving it a top-line efficacy of 100% in this age group.

The results were in line with the adult COVE study, which formed the basis for an emergency use authorisation (EUA) for Moderna's vaccine in December 2020. The primary endpoint was non-inferior immunogenicity compared to the COVE data set.

As the incidence of COVID-19 is lower in adolescents, TeenCOVE also used a secondary set of efficacy criteria for milder cases of the infection, with results there showing that mRNA-1273 had an efficacy of 93% in seronegative participants starting 14 days after the first dose.

So far, only the Pfizer/BioNTech vaccine, which is also derived from mRNA, has been cleared for use in younger people in the US, getting the go-ahead earlier this month for 12 to 15 year olds. Emergency use approval for people aged 16 and over was granted last December.

Assuming it gets an EUA, Moderna's mRNA-1273 vaccine will ramp up the availability of supplies for middle and high school-age children in the US ahead of the start of the next school year. The FDA only took four weeks to expand the authorised age-range for the Pfizer/BioNTech shot.

The Centres for Disease Control and Prevention (CDC) started recommending that people aged 12 and over get vaccinated against COVID-19 earlier this month after the Pfizer/BioNTech jab was approved, opening a new front in the fight against the coronavirus pandemic.

Moderna is also testing its vaccine in the 7,000-subject KidCOVE study in children aged six months to 11 years, which started enrolling participants in March.

With the US adult vaccination programme now in full swing, and at least 25 states plus Washington DC having fully vaccinated at least half of their adult populations, attention is now turning to the rollout in younger people.

According to the CDC, the US has already immunised around 600,000 children aged between 12 and 15, and intends to go even younger once safety data in younger children becomes available.

That poses an ethical dilemma of course, as COVID-19 in children is rarely serious and there are strong arguments for diverting doses to adults in other countries that currently have much less access to vaccines.

A recent study in The Lancet medical journal found that fewer than two out of every million children with COVID-19 in the US, UK, Italy, Germany, Spain, France, and South Korea died during the pandemic.

On the other hand, some argue that it will be impossible to get herd immunity to COVID-19 unless there is widespread vaccination of children to interrupt transmission – although the rapid emergence of new variants suggests herd immunity may not be a realistic goal.

There are also safety considerations, in particular "several dozen" cases of heart inflammation seen mainly in young people taking the Moderna and Pfizer/BioNTech shots which are being investigated by the CDC.

This week, the American Heart Association (AHA) and American Stroke Association (ASA) said people aged over 12 should continue to receive the shots as their benefits "enormously outweigh the rare, possible risk of heart-related complications."