Trudeau says promising new Pfizer vaccine could be 'light at the end of the tunnel'

Prime Minister Justin Trudeau said today that Pfizer's promising COVID-19 vaccine trial is an "encouraging" development — and could be the first step toward restoring Canada's social and economic life.

If all goes well, he said, the Pfizer vaccine should be available to Canadians sometime over the first three months of 2021.

"We see the light at the end of the tunnel," Trudeau told a COVID-19 briefing with reporters today. "We are hopeful we are getting there because our scientists are working incredibly hard."

U.S.-based pharmaceutical giant Pfizer said today an early analysis of its novel coronavirus vaccine trial suggested the vaccine was more than 90 per cent effective in preventing the disease among trial participants who had no evidence of prior coronavirus infection.

Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, called the trial results "extraordinary" and said Pfizer's success bodes well for a similar vaccine being developed by U.S. firm Moderna.

"Today is a great day for science and humanity," said Dr. Albert Bourla, chairman and CEO of Pfizer.

Canada already has placed orders with Pfizer and its German partner BioNTech for 20 million doses of the two-dose vaccine so that it can be deployed here as soon as the company gets the necessary regulatory approvals from Health Canada.

Pfizer has been submitting trial data to the regulator on a rolling basis since October 9. The rolling review allows drug makers to bypass the lengthy timelines they normally face when launching a new product. The vaccine will be approved for use once Health Canada is sure of its safety, efficacy and quality.

Trudeau said that while Pfizer's results are promising, Canadians must continue to adhere to public health guidelines to keep caseloads manageable.

"It's really important we double down on our efforts," he said. "We need to make sure we are controlling the spread of COVID-19 in the coming months so that when vaccines get here, we will be able to act quickly to protect all Canadians."

WATCH: Trudeau discusses Pfizer's promising COVID-19 vaccine

Pfizer said it would continue to monitor for trial-related concerns in the weeks ahead and it expects to have its final safety data by the third week of November.

The drug maker said it is now readying an application to the U.S. Food and Drug Administration (FDA) for emergency use authorization to deploy the vaccine for use on some people in the U.S. by year's end.

Based on current projections, Pfizer has said it expects to produce more than 50 million doses in 2020 and up to 1.3 billion doses in 2021.

Dr. Zain Chagla, a professor of medicine at McMaster University and an expert in infectious diseases, cautioned against hyping results before long-term safety and efficacy data have been collected.

He pointed out that the Pfizer trial results were published in a press release and not in a peer-reviewed independent medical journal.

Still, Chagla said, the Pfizer development could be a major medical breakthrough that could help return the world to normalcy.

"The 90 per cent reduction in symptomatic COVID-19 is incredibly effective, way higher than the the thresholds that the World Health Organization and the FDA had set," Chagla told CBC News. The FDA announced this summer that in order for an experimental COVID-19 vaccine to get the green light, it would need to be safe and "prevent disease or decrease its severity in at least 50 per cent of people who are vaccinated."

"This is a strong checkmark for things to progress with this vaccine and hopefully make it to the market," he said.

Dr. Isaac Bogoch, an expert on infectious diseases at the University of Toronto, also cautioned against "science by press release" — but added that if the trial results hold up, the world could have COVID-19 on the run.

"We always have to be skeptical, we always have to see the actual clinical data, but if the vaccine can truly reduce the risk of getting COVID-19 by 90 per cent, and if people are truly protected after that second dose ... I mean, clearly, that would be a major win," he said.

The rollout of a vaccine will be guided by Canada's National Advisory Committee on Immunization (NACI), which has said the most vulnerable and those most likely to die from contracting the virus should be first in line for shots.

People living in long-term care homes, those with compromised immune systems, the elderly and essential workers like front line health care staff and grocery store employees likely will have access to a vaccine before the general population.

"We've secured already millions of doses of that vaccine candidate and when it is safe to distribute, we will certainly be beginning distribution in Canada to high priority groups," Trudeau said.

This particular vaccine must be stored at -75 C — which could make the logistics of distribution "more complex," Trudeau said. Other vaccines are in the development pipeline that do not require such stringent storage requirements, he added.

The Pfizer vaccine is just one candidate that Canada is pursuing. In October, the government signed a contract to procure 76 million doses from the Quebec City-biotech company Medicago.

Medicago is developing the vaccine in partnership with the British drug company GlaxoSmithKline. The two companies have said its pre-clinical results show the vaccine demonstrated a "high level of neutralizing antibodies following a single dose."

All told, the federal government has secured 358 million doses of COVID-19 vaccines from seven different companies — an insurance policy if some of the vaccines in development prove to be ineffective in clinical trials.