Health Canada has authorized the first COVID-19 vaccine for children, giving the regulatory green light to Pfizer-BioNTech’s two-dose vaccine, meaning kids across the country will soon be able to receive additional protection against the novel coronavirus.

Children ages five- to 11-years old are now eligible to get vaccinated with a dosage that is one third the size that has been offered to those aged 12 and older.

The first shipment of these pediatric doses will arrive on Sunday, with a total of 2.9 million doses landing by the end of next week.

“That’s enough doses to offer a first shot to all eligible children in this country,” Procurement Minister Filomena Tassi said Friday.

While Health Canada has approved the doses to be given 21 days apart, the National Advisory Committee on Immunization (NACI) is recommending an interval of eight weeks or more between the first and second doses.

“This is the first COVID-19 vaccine authorized in Canada for use in this age group and marks a major milestone in Canadas fight against COVID-19,” said Canada’s regulatory agency in a statement. “After a thorough and independent scientific review of the evidence, the Department has determined that the benefits of this vaccine for children between 5 and 11 years of age outweigh the risks.”

In an interview on CTV News Channel’s Power Play, Health Minister Jean-Yves Duclos said that these doses can start to be administered next week, but couldn’t confirm when further doses to cover second shots will be arriving, other than to say he anticipates it’ll be in time to meet NACI’s eight week interval recommendation.

During a press conference discussing the long-anticipated authorization, Health Canadas chief medical adviser Dr. Supriya Sharma said that the formulation approved for children is “slightly different” than the version authorized for adults, but the immune responses were “comparable.”

“The main adverse events reported were similar to those and in adolescents and young adults, but were less frequent, except for redness and swelling at the injection site, which were slightly higher. Other adverse events reported included fatigue, and headache. Most reactions were mild to moderate in severity, and resolved quickly on their own,” Sharma said of the clinical and safety data evaluated by Health Canada.

Pfizer Canada says that steps have been taken to differentiate the pediatric formulation vials from the adult version, including putting an orange cap on the version for kids.

Health Canada had been prioritizing the review of Pfizer’s submission to use its vaccine in those ages five to 11 since Oct. 18, and a similar review is ongoing for Moderna’s two-dose mRNA vaccine for those ages six to 11. 

“This is an exciting moment, and its a day that many parents across the country have been eager to wait for and this is the opportunity for them to start to immunize their school-based children,” said Pfizer Canada vaccines lead Fabien Paquette in an interview.

According to Health Canada’s authorization, clinical trials have shown that the Pfizer vaccine was 95 per cent effective in protecting trial participants from COVID-19 for those 16 years and older, 100 per cent effective for those 12 to 15 years old, and 90.7 per cent effective for those five to 11 years old.

Sharma said that in the data reviewed by Health Canada, the four reported serious adverse events were ultimately determined to be unrelated to vaccination, and there were no reports of myocarditis, pericarditis, or severe allergic reactions.

Dr. Tam said that evidence emerging from adult immunization indicates that longer intervals between doses results in a longer-lasting immune response, and may lower the risk of myocarditis and pericarditis.

NACI is recommending that, unless otherwise advised by their doctor, children have a 14-day interval between receiving any other vaccines and the COVID-19 shot, calling it a “precaution” to help determine the possible cause of any side-effects that may arise.

Paquette said that NACI’s suggestion for a longer interval is based on its own analysis, and that Pfizer’s submission was based off of its studies using a 21 day wait between doses.

“A longer interval has not been studied with this age group,” he said.

Should NACI’s dose interval be observed by provinces and territories, it means that those aged five to 11 will not be able to be fully vaccinated before the Christmas holiday season. Sharma suggested that if families have specific dosing concerns related to holiday or travel plans, they could discuss their situation with healthcare practitioners.

Still, Dr. Tam is viewing the authorization as a “welcome additional prevention option,” given “the current and prevailing epidemiology of COVID-19 in Canada, where incidence rates have remained highest in children aged five to 11 years for most of the fourth wave.”

The Public Health Agency of Canada says there will be efforts taken to inform parents and encourage them to vaccinate their children, but in her view, Tam doesn’t think now is the time to be discussing implementing an extension of vaccine mandates to children.

“We shouldn’t include a pediatric mandate at this point… There’s very little access anywhere else in the world to pediatric vaccines, we’re one of the first countries… And so for the purposes of travel for example, I don’t expect that we will be requiring this,” she said.

“During this time, it is very important that we support children and their caregivers and making informed decisions about COVID-19 vaccination while respecting their choices and pace of decision making,” Tam said.

Referencing potential hesitancy, Sharma said that she understands the worry about what might happen, but “not choosing to get the vaccine for your children is also a choice.”

Reacting to the news, CTV News medical specialist Dr. Marla Shapiro said that the side-effects from COVID-19 vaccines are “well outweighed” by the risks associated with a COVID-19 infection.

“Mostly, what we expect to see is sore arms, redness, maybe a little bit of flu like symptoms if some kids experience that… But every parent has to ask their questions, be comfortable with their decision, and I think its really to understand whats the downside of not getting vaccinated and then the risk of getting COVID in a child,” she said on CTV News Channel.

Pfizer will be required to continue providing Canada with safety and efficacy information from ongoing studies and real-world usage, with Health Canada and the Public Health Agency of Canada pledging to “closely monitor” the usage of this vaccine, which has been given the brand name of “Comirnaty.”

Sharma had been signalling for a few weeks that the authorization was around the corner, and in anticipation provinces and territories have been putting plans in place to administer these doses as soon as supply is ready.

Officials have previously stated that Canada has enough syringes and other supplies necessary to administer the pediatric COVID-19 vaccines.

“We are working closely with Pfizer to firm up the exact schedule for delivery of the second doses, and we all have more information to share about that soon,” Tassi said.