The Pfizer-BioNTech vaccine has now proved 95% effective in preventing coronavirus and has met the safety criteria needed for emergency authorisation, the firms have said.
Pfizer and BioNTech say they plan to submit the COVID-19 vaccine to the US regulator for emergency use approval “within days” after “no serious safety concerns” were reported.
The UK regulator, the Medicines and Healthcare products Regulatory Agency (MHRA), is also poised to fast-track authorisation of the vaccine after the government ordered enough for 20 million people.
Pfizer was the first company in the world to share results of Phase 3 trials
Final efficacy analysis of the jab showed 95% were protected from the virus within 28 days of the first dose – up from when results of Phase 3 trials were shared last week.
It also proved 94% effective among adults over the age of 65 – who are generally more vulnerable.
There were no serious side effects, with only 2% of the 43,000 participants reporting a headache and 3.7% reporting fatigue, the companies said.
On 9 November, Pfizer became the first company in the world to complete Phase 3 of its coronavirus vaccine trials, which showed 90% efficacy.
The news was followed earlier this week by an announcement from US pharmaceutical firm Moderna that its own vaccine candidate had a similarly promising efficacy of 94.5%.
So far the UK government has ordered 40 million doses of the Pfizer-BioNTech jab – enough for 20 million people – and five million – for use on 2.5 million patients – of the Moderna one.
The US and German companies say they will be able to produce 50 million doses this year and 1.3 billion in 2021.
Pfizer chairman and chief executive Dr Albert Bourla said: “The study results mark an important step in this historic eight-month journey to bring forward a vaccine capable of helping to end this devastating pandemic.
“We continue to move at the speed of science to compile all the data collected thus far and share with regulators around the world.”
Pfizer and Moderna’s vaccine trials are two of around 12 worldwide, including one being developed by AstraZeneca and Oxford University, that are in the final stages of testing.
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COVID-19 vaccine: Will it end the crisis?
Analysis: Most significant news yet provides massive tick in the COVID vaccine wish-list
By Thomas Moore, science correspondent
Of all the exciting recent news on COVID vaccines, this is perhaps the most significant of all.
The Pfizer-BioNTech vaccine works in the people who need it the most. In the over-65s it was over 94% effective against the disease.
It’s a massive tick in the wish-list for a vaccine.
The immune systems of older people don’t generally work as well as those of the young.
But the latest data shows the vaccine is just about as effective in people of all ages.
The companies also say the overall effectiveness of the vaccine is now 95%, up from the 90% suggested by the interim analysis last week.
That’s the same as the Moderna vaccine, which uses similar technology.
The clinical trials on just over 43,000 volunteers found no serious safety concerns. A few had headaches and fatigue, but that’s not unusual for a vaccine.
One big scientific question remains. How long does immunity last? If people need regular booster doses that will stretch manufacturing capacity still further.
The answer to that will come from the ongoing monitoring of antibody and T-cell levels in people who have had the vaccine.
In the short term, the success of this vaccine will depend on the logistics.
Its activity depends on the dry ice and heavily insulated container that keeps it at minus 70C for up to 15 days. Raise the temperature by just 10 degrees and it may not work.
It’s a smart and effective vaccine. Now the NHS and its suppliers need to get it where it’s needed, and fast.