Health Canada is expected to announce the authorization of Moderna's Omicron-targeting bivalent COVID-19 vaccine on Thursday, CTV News has confirmed through senior government sources.

Moderna submitted its bivalent booster to Health Canada for regulatory approval on June 30, with aims to have it available this fall.

The booster shot was submitted by Moderna for approval for ages 12 and over. It targets both the original strain of COVID-19 as well as the Omicron variant.

The federal government has already purchased 12 million doses of the vaccine, with supply expected this year. 

Pfizer-BioNTech has also submitted its bivalent booster for regulatory assessment. That submission went in to Canada’s federal health regulator on July 25.

"Our regulatory colleagues in Health Canada are working very fast at reviewing the submissions from Moderna and from Pfizer-BioNTech on the bivalent booster doses," said Chief Public Health Officer Dr. Theresa Tam during a press conference on Aug. 22.

"We also have secured sufficient supply of the bivalent formulation should the regulatory authorities go on to authorize the vaccines," Tam said.

Questions have been raised about whether Canadians should be waiting for the bivalent doses to become available before rolling up their sleeve for an additional dose, something Tam has said is a decision that should be taken based off of individual risk factors

Following a technical briefing with Public Health Agency of Canada officials on Thursday, Health Minister Jean-Yves Duclos is scheduled to make an announcement about "the importance of COVID-19 vaccination as we head into the fall."

With files from CTV News' Mackenzie Gray and Kevin Gallagher