Prime Minister Justin Trudeau said Monday he was encouraged by Pfizer and BioNTech's announcement that their Covid-19 vaccine in trials proved 90 percent effective, adding it could be available in Canada in early 2021.

The two pharmaceutical companies said the vaccine they have jointly developed had during Phase 3 trials provided protection to nearly all patients seven days after the second of two vaccine doses.

At a news conference, Trudeau called the results "promising." "We see the light at the end of the tunnel," he said.

The prime minister said he expects the vaccine to be distributed to Canadians "most likely in the first three months of 2021." 

"But," he added, "there is a lot of uncertainty involved in these processes."

Canada signed a deal with US giant Pfizer and its German partner BioNTech in August for a minimum of 20 million doses of their vaccine. 

It was at the time the most advanced vaccine candidate in development among several of which Canada secured access.

Other agreements were signed with AstraZeneca, Sanofi and GSK, Novavax, Johnson & Johnson, Medicago and Moderna for a total of more than 300 million doses for its population of 38 million.

Trudeau noted that the Pfizer-BioNTech vaccine poses some "logistical distribution" challenges, including that it must be stored at very cold temperatures and therefore getting it to Canadians will be "more complex and slightly more limiting."

"We are already working on those necessary logistical supports," he said.

Trudeau also said that testing of several other vaccine candidates was "progressing well" and some of those could be rolled out in early 2021 too. 

Until then, he encouraged Canadians to continue to take precautions to limit the spread of the Covid-19 illness, including social distancing and wearing masks.

As of Monday, Canada has reported more than 260,000 Covid-19 infections, including 10,500 deaths.

"To be very clear: If you catch Covid in the coming days and weeks, a vaccine won't help you or your family," Trudeau concluded.