Canada has become the second country after the US to approve Moderna's coronavirus vaccine, paving the way for health authorities to step up an inoculation campaign against a worsening second wave.
Earlier this month, Ottawa gave the green light to the Pfizer-BioNTech vaccine, which authorities have begun administering to priority groups including health workers and the elderly.
So far Canada has received a small fraction of the 76 million doses it needs.
"After a thorough, independent review of the evidence, it has been determined that the Moderna vaccine meets the department's stringent safety, efficacy and quality requirements," the federal health ministry said in a statement.
The United States approved the Moderna vaccine last Friday.
It needs to be stored and shipped frozen, but does not require the ultra-cold temperatures of the shot Pfizer developed in partnership with German firm BioNTech.
"(This means) it can be distributed to isolated and remote communities," the health ministry said.
Prime Minister Justin Trudeau said on December 15 that Canada had signed a deal to receive up to 168,000 doses of the Moderna vaccine before the end of December once regulators had given their final approval.
A second COVID-19 wave is sweeping Canada and medical officials in some parts of the country say the healthcare system is under dangerous strain.
Canada has so far recorded 521,509 infections and 14,425 deaths.
One potential threat is a new more-infectious variant of the virus detected in Britain.
Canada imposed a 72-hour ban on flights from the UK on Monday and is set to announce later on Wednesday whether that measure will be extended.