Moderna expects to seek Canadian approval of COVID-19 vaccine for children under 6 'shortly'

Moderna says it's working on a submission to Health Canada for the approval a COVID-19 vaccine for children under the age of six.

Moderna has already submitted data about use of the vaccine in babies, toddlers and preschoolers in the U.S.

Moderna on Thursday filed for U.S. government authorization to become the first company granted permission for a COVID-19 vaccine for children under the age of six. (Dado Ruvic/Reuters)

Moderna says it's working on a submission to Health Canada for the approval a COVID-19 vaccine for children under the age of six.

The biotech company on Thursday asked U.S. regulators to authorize low doses of its vaccine for children between six months and five years of age. The long-awaited move is another stride toward potentially opening shots for millions of tots by summer.

In Canada, Moderna says it hopes to complete the application for regulatory approval of its COVID-19 vaccine, Spikevax, "shortly."

To date, Health Canada has only approved mRNA COVID-19 vaccines for children over the age of five.

10% of Canadian cases in kids under 11

The Pfizer-BioNTech vaccine, Comirnaty, is available for children aged five to 11, and Moderna Spikevax is available for children six to 11 years old. About 41 per cent of Canadian children in this cohort have had two shots, according to federal data, while 56 per cent have received at least one dose.

Frustrated families are waiting impatiently for a chance to protect the littlest kids as all around them people shed masks and other public health precautions — even though highly contagious coronavirus mutants continue to spread.

Already about three-quarters of U.S. children of all ages show signs they've been infected at some point during the pandemic.

In Canada, federal data states 10.8 per cent of reported cases were in children up to 11 years old.

Dr. Francis Lee, right, puts a bandage on Jacob Wolak, 10, after giving him a COVID-19 vaccine in Vancouver, Nov. 29, 2021. (Maggie MacPherson/CBC)

Moderna submitted data to the Food and Drug Administration that it hopes will prove two low-dose shots can protect babies, toddlers and preschoolers — albeit not as effectively during the Omicron surge as earlier in the pandemic.

"There is an important unmet medical need here with these youngest kids," Dr. Paul Burton, Moderna's chief medical officer, told The Associated Press. Two kid-size shots "will safely protect them. I think it is likely that over time they will need additional doses. But we're working on that."

As in Canada, children ages five or older in the U.S. can be vaccinated using rival Pfizer's vaccine, leaving 18 million younger tots unprotected.

Moderna's vaccine isn't the only one in the race. Pfizer is soon expected to announce if three of its even smaller-dose shots work for the littlest kids, months after the disappointing discovery that two doses weren't quite strong enough.

Questions swirling about what's taking so long

Whether it's one company's shots or both, FDA vaccine chief Dr. Peter Marks said the agency will "move quickly without sacrificing our standards" in deciding if tot-sized doses are safe and effective.

While questions are swirling about what's taking so long, Marks pointedly told lawmakers this week that the FDA can't evaluate a product until a manufacturer completes its application. In a statement Thursday, the FDA said it will schedule a meeting to publicly debate Moderna's evidence with its independent scientific advisers but that the company still must submit some additional data. Moderna expects to do so within weeks.

"It's critically important that we have the proper evaluation so that parents will have trust in any vaccines that we authorize," Marks told a Senate committee.

If FDA clears vaccinations for the littlest, next the Centers for Disease Control and Prevention would have to recommend who needs them — all tots or just those at higher risk from COVID-19.

"It's very important to get the youngest children vaccinated" but "moving quickly doesn't mean moving sloppily," said Dr. Philip Landrigan, a pediatrician and public health expert at Boston College. FDA must "see if it's safe. They need to see if it's effective. And they need to do so swiftly. But they won't cut corners."

'Kind of left behind'

Many parents are desperate for whichever vaccine gets to the scientific finish line first.

"We've been kind of left behind as everybody else moves on," said Meagan Dunphy-Daly, a Duke University marine biologist whose six-year-old daughter is vaccinated — but whose three-year-old and 18-month-old sons are part of Pfizer's trial.

The family continues to mask and take other precautions until it's clear if the boys got real vaccine or dummy shots. If it turns out they weren't protected in the Pfizer study and Moderna's shots are cleared first, Dunphy-Daly said she'd seek them for her sons.

"I will feel such a sense of relief when I know my boys are vaccinated and that the risk of them getting a serious infection is so low," she said.

The FDA will face some complex questions.

WATCH | Moderna says its low-dose vaccine is safe for little kids:

Moderna’s low-dose vaccine is safe for kids under 6, company says

5 months ago
Duration 1:55
Early results show promising signs for Moderna’s low-dose COVID-19 vaccine in kids under the age of 6, with study participants developing a high level of antibodies. Moderna plans to file for vaccine authorization in Canada later this spring.

In a study of kids ages six months through five years, two Moderna shots — each a quarter of the regular dose — triggered high levels of virus-fighting antibodies, the same amount proven to protect young adults, Burton said. There were no serious side-effects, and the shots triggered fewer fevers than other routine vaccinations.

But the vaccine proved between about 40 per and 50 per cent effective at preventing symptomatic COVID-19 during the trial. Burton blamed the Omicron variant's ability to partially evade vaccine immunity, noting that unboosted adults showed similarly less effectiveness against milder Omicron infections.

While no children became severely ill during the study, he said high antibody levels are a proxy for protection against more serious illness — and the company will test a child booster dose.

"That's not totally out of the realm of what we would have expected," said Dr. Bill Muller of Northwestern University, who helped with Moderna's child studies. "Down the road I would anticipate it's going to be a three-shot series."

Another issue: So far in the U.S., Moderna's vaccine is restricted to adults. Other countries have expanded the shot to kids as young as six. But months ago the FDA cited concern about a rare side-effect, heart inflammation, in teen boys, and it hasn't ruled on Moderna's earlier pediatric applications.

Burton said the FDA may consider its vaccine for children of all ages — but also might open it first to the youngest kids who have no other option. He said safety data from millions of older children given Moderna vaccinations abroad should help reassure parents.

A struggle to get kids vaccinated

Vaccinating eligible children against the coronavirus has been a struggle for many developed countries, with most North American and European countries starting their child inoculation drives between November and January.

Immunization rates are below 15 per cent among European children aged between five and nine, the youngest age group for which COVID-19 vaccines have been authorized there.

In the U.S., 28 per cent of children five to 11 as of April 20 were considered fully vaccinated, with 35 per cent having received at least one dose.

Canada has fared better than most Western countries in vaccinating the youngest eligible children, but federal and provincial health officials have said they would like to see the rate rise even more.

With files from CBC News and The Associated Press