Pfizer says final results show coronavirus vaccine is 95% effective, no safety concerns

Pharmaceutical company Pfizer said Wednesday that the final analysis from its clinical trial shows its coronavirus vaccine is 95 per cent effective, has no serious side effects, and protects older adults.

The results from the final efficacy analysis of the vaccine study were released Wednesday.

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The announcement comes a week after Pfizer revealed promising preliminary results of its Phase 3 trials. The company is now preparing to formally ask U.S. regulators to allow the emergency use of the vaccine.

In the Phase 3 study involving more than 43,000 volunteers, half received the experimental vaccine and half got a placebo. Participants received two shots that were spaced 21 days apart.

Pfizer said on Wednesday there had been 170 cases of coronavirus in its trial, of which 162 were in the placebo group and eight were in the vaccine group.

Ten people developed severe COVID-19, one of whom received the vaccine, the data showed.

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The results said that the vaccine appeared to protect 94 per cent of adults over 65 years old — a demographic that is at particular risk from the virus.

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Pfizer also said the vaccine prevented mild and severe forms of the virus, that it was well-tolerated, and that side effects were mostly mild to moderate and cleared up quickly.

The only severe, adverse event was fatigue, which affected 3.7 per cent of recipients after the second dose. Older adults tended to report fewer and milder adverse events following vaccination.

Pfizer has not yet released detailed data on its study, and results have not been analyzed by independent experts.

Pfizer and BioNTech said they expect to produce up to 50 million vaccine doses globally in 2020 and up to 1.3 billion doses in 2021.

Canada has signed a deal with Pfizer in August to secure 20 million doses of the coronavirus vaccine in 2021. Prime Minister Justin Trudeau previously said he hopes to have the vaccine rollout in early 2021.

On Tuesday, Moderna announced that its experimental vaccine appears to be 94.5 per cent effective after an interim analysis of its late-stage study.

— With files from the Associated Press and Reuters