Health Canada approves Moderna's updated COVID-19 vaccine

Health Canada has approved Moderna's updated COVID-19 vaccine for all Canadians who are six months of age and older — while two other options for fall shots remain in the regulatory pipeline.

Federal officials announced the approval on Tuesday morning, more than two months after Moderna submitted its new formulation. The mRNA-based shot is monovalent, targeting just the Omicron XBB.1.5 subvariant, which means the vaccine is more tailored to the virus strains currently circulating.

The company told CBC News that its first newly approved doses should arrive in Canada "by tomorrow" and will continue to arrive over the course of the month, while Canadian officials expect deliveries to the provinces will start in October.

"I know we all wish COVID-19 no longer existed, but people are still getting infected, and vaccination continues to be one of the most effective ways to protect ourselves against serious outcomes," said Dr. Supriya Sharma, chief medical advisor at Health Canada, during a technical briefing. 

Health Canada said Canadians age five and up should receive one dose, regardless of their COVID vaccination history. Meanwhile children from six months to four years old should receive two doses if they have not been previously vaccinated with a COVID vaccine, or one dose if they've previously had at least one dose.

Notably, federal officials aren't calling the shots boosters but instead stressed that these are updated options more similar to an annual flu shot. The COVID situation hasn't stabilized quite yet, Sharma said.

"The idea is we'll get to a place where it will be much more like the flu vaccines where people may be on a regular schedule, getting an updated vaccine," she said.

As for the best time to get another COVID shot, the department suggests waiting six months after your last dose since protection against infection does wane over time — though scientists say protection against serious illness is longer-lasting.

On Tuesday, Canada's national vaccine advisory body also reaffirmed its advice from earlier this summer, stressing that vaccination is particularly important for anyone at an increased risk of severe disease, including seniors age 65 and up, residents of congregate living settings such as long-term care facilities, pregnant individuals and anyone with underlying medical conditions who may heightened their risk. 

The guidance also applies to people who provide essential community services and members of racialized, First Nations, Métis and Inuit communities.

Health Canada is still reviewing submissions on a "priority basis" for updated shots from other drugmakers as well, including Pfizer-BioNTech's Omicron XBB.1.5 vaccine for Canadians age six months and up and Novavax's shot for people age 12 and up.

"We will have enough supply of the updated COVID-19 vaccines to support immunization programs across Canada," said Canada's chief public health officer, Dr. Theresa Tam, at the federal briefing.

Dr. Lynora Saxinger, an infectious diseases specialist at the University of Alberta in Edmonton, said even if Canadians have "booster fatigue," these types of updated vaccines will be important shots to get this fall.

"The original strain now is kind of irrelevant to what's circulating," she said. "But the XBB booster covers most of the important mutations that we're seeing in the alphabet soup of variants that everyone's watching right now.