OTTAWA -- Canada's hopes of speeding up COVID-19 vaccinations brightened slightly over the weekend as regulators began work to approve a new inoculation, even as the federal government sought to head off any restrictions on vaccine shipments from Europe.

Pharmaceutical company Novavax quietly submitted its COVID-19 vaccine to Health Canada for regulatory approval on Friday, less than two weeks after Ottawa finalized a deal with the Maryland-based company for 52 million doses of the shot.

Because of the emergency nature of the pandemic Health Canada is accepting applications for vaccines before the final trial data is ready, allowing the review team to start pouring over the documents on an ongoing basis, rather than waiting until everything is finished.

The rolling review allows for much faster approval once the final results from clinical trials are complete.

"Health Canada is expediting the review of all COVID-19 vaccines," Health Canada spokesman Andre Gagnon said in an email. "This is being done through rolling submissions, where data is being reviewed as it becomes available from the manufacturer."

Novavax is the fifth vaccine maker to submit an application for rolling review. AstraZeneca, Pfizer-BioNTech and Moderna all submitted in early October, and Johnson and Johnson followed suit at the end of November.

Health Canada approved the Pfizer-BioNTech vaccine on Dec. 9 and gave Moderna the green light on Dec. 23, both about three weeks after the companies completed their Phase 3 trials. A decision on AstraZeneca is expected in the next couple of weeks.

Johnson and Johnson reported results from its Phase 3 trial just last week.

Novavax also reported results Thursday from a trial in the United Kingdom, but a large trial in the U.S. is still at least a month or two away from yielding final results.

The company has said its vaccine was 89 per cent effective in the U.K. trial. It also touts its product as very effective against the new British and South African strains of COVID-19, and says it could start delivering doses in the spring once it has received regulatory approval.

"The doses that will ultimately be sent to Canada are being made outside the U.S.," Novavax spokeswoman Amy Speak said in an email.

Novavax's application comes as the federal Liberal government faces withering criticism for the pace of vaccinations across the country, with opposition parties and some provincial governments complaining about a lack of shots.

Those critiques have come as Pfizer slows delivery of its vaccines to Canada so it can expand a production plant in Belgium. The European pharmaceutical giant is also pressing Canada to allow six shots per vial of vaccine instead of the current five.

Moderna has also said that it will deliver fewer doses than originally promised, though the Liberal government insists the slowdowns are temporary and that both companies will make good on their promised deliveries over the coming months.

There are also concerns that Canada's troubled vaccine supplies will be further affected by new controls on vaccine exports that have been imposed by the European Union, which is also struggling with delivery shortfalls from manufacturers.

The measures allow the European Union to deny vaccine exports if the manufacturer has not fulfilled its promised deliveries to the 27-country bloc, which is where most of Canada's shots are being made.

Ottawa has been working to head off any impact on Canada's supply, with International Trade Minister Mary Ng speaking by phone to her EU counterpart on Saturday for the second time in three days.

That follows Prime Minister Justin Trudeau's own phone call with European Commission President Ursula von der Leyen late last week, after which Trudeau asserted that the new export controls would not affect vaccines destined for Canada.

Ng was told the same thing during her phone call with Valdis Dombrovskis, the European Commission's commissioner for trade, according to a summary of their conversation provided by Global Affairs Canada.

The federal department said Ng's call was "part of a broader ongoing engagement across government ... to minimize any impact of the EU's Transparency and Authorization Mechanism on vaccines manufactured in Europe destined for Canada," the summary read.

Former Canadian diplomat Colin Robertson, who is now vice-president of the Canadian Global Affairs Institute, said the number of calls between the government and European officials -- and the fact they have been revealed publicly -- is unusual and "is the kind of thing you would do if you're concerned."

Robertson nonetheless expressed his hopes that Ottawa's close relationship with the EU, formalized in various trade and political agreements, along with the contracts between Ottawa and the drug companies would prevent the Europeans from curtailing shipments to Canada.

Von der Leyen said Friday the commission is following through on a threat to force COVID-19 vaccine makers to show them what vaccines they are producing in Europe and where those are going.

She said the export transparency rule is temporary but has to be done as the continent is in an ongoing battle with vaccine-makers about slow deliveries.

Both Pfizer-BioNTech and AstraZeneca are behind on their scheduled deliveries to European nations, but it is the latter with which Europe is having the loudest fight.

The EU is demanding the company ship doses made in the United Kingdom to make up for shortfalls due to production issues in its European plants.

This report by The Canadian Press was first published Jan. 31, 2021.

With files from Mia Rabson.