Pfizer coronavirus vaccine is 90% effective, early data suggests


coronavirus vaccine developed by Pfizer and BioNTech may be more than 90 per cent effective in preventing the disease, the two pharmaceutical firms said as they released interim data from their ongoing large-scale trial.

The vaccine has been tested on 43,500 people in six countries and no safety concerns have been raised, with Dr Albert Bourla, Pfizer chairman and chief executive, calling it “a great day for science and humanity”.

Preliminary analysis, conducted by an independent data monitoring board, looked at 94 infections recorded so far in the vaccine’s phase 3 study.

Of those participants who were infected with Covid-19, it is currently unclear how many had received the vaccine versus those who had been given a placebo. The current efficacy rate, which is much better than most experts expected, implies that no more than eight volunteers will have been inoculated.

The data has yet to be publicly released or peer-reviewed, and Pfizer said the initial protection rate might change by the time the study ends.

The longevity of the immune response provoked by the mRNA-based vaccine also remains unknown.

However, the findings are the most promising indication to date that a vaccine will be effective in preventing disease among infected individuals, handing humanity a crucial tool in tackling the pandemic.

US president-elect Joe Biden said the vaccine “promises the chance to change” the realities of the Covid crisis, but insisted that widespread vaccination remains months away. He warned that people will need to continue wearing masks and maintain social distancing.

“Today’s news is great news,” Mr Biden said. “But the tasks before us now remain the same.”

Professor Sir John Bell, a member of the government’s Scientific Advisory Group for Emergencies, said he was confident that life in the UK would start returning to normality by next spring – assuming regulatory approval for the vaccine is granted.

“I’m probably the first guy to say that but I will say that with some confidence,” he told the BBC.

“I am really delighted with this result – it shows that you can make a vaccine against this little critter. Ninety percent is an amazing level of efficacy.”

Pfizer and its German partner BioTech will continue with the phase 3 trial until 164 infections have been reported among volunteers – a figure that will give regulatory authorities a clearer idea of the vaccine’s efficacy.

This number is expected to be reached by early December in light of the rising US infection rates, Pfizer said.

The two companies said they have so far found no serious safety concerns and expect to seek US emergency use authorisation later this month.

Pfizer’s Dr Bourla said in a statement: “We are reaching this critical milestone in our vaccine development program at a time when the world needs it most with infection rates setting new records, hospitals nearing over-capacity and economies struggling to reopen.”

According to Pfizer, protection is achieved 28 days after the initiation of the vaccination, which consists of two doses.

Authorities have stressed that initial supplies of the vaccine will be limited. An estimated 50 million doses, enough to vaccinate 25 million people, are expected to be available by the end of the year.

From there, Pfizer aims to manufacture a total of 1.3 billion doses throughout 2021.

Pfizer and BioNTech have a £1.48bn contract with the US government to deliver 100 million vaccine doses beginning this year. They have also reached supply agreements with the European Union, the UK, Canada and Japan.

The UK has ordered 40 million doses, 10 million of which are due to be delivered by the end of the year, No 10 said on Monday.

Ian Jones, a professor of virology at the University of Reading, said the Pfizer/BioNTech vaccine “always looked like the most bang-per-buck as it is entirely focused on the part of the virus that binds to the human cell, the receptor binding domain.”

He added: “The only things we will not know for some time is the longevity of the response in all age groups, but assuming antibody titres are high that should be at least as good as any other vaccine currently in trial.”

Dr Michael Head, senior research fellow in global health at University of Southampton, said the results appeared “excellent” but he called for caution.

“This cautiously sounds like an excellent result from the phase three trials, but we should remain a little cautious,” he said. “The provisional findings are made available in a press release and the study is ongoing.”

The Pfizer jab uses messenger RNA (mRNA) technology, which relies on synthetically-produced genetic coding that generates an immune response in humans, and is produced at scale more rapidly than conventional vaccines.

A number of other vaccines that use the same platform are also in development, including the Moderna jab, raising hope that these candidates will be similarly effective.

Richard Hatchett, chief executive of the Coalition for Epidemic Preparedness Innovations (Cepi), said: “We believe these interim results also increase the probability of success of other Covid-19 candidate vaccines which use a similar approach.”

However, this type of vaccine needs to be stored at temperatures as low as -80C, which is expected to hinder the distribution of doses across the world.

“This could create major logistical challenges for mass treatment outside major urban areas and in low or middle income countries,” said Andrew Hill, a senior visiting research fellow in the department of pharmacology at the University of Liverpool.

The FTSE 100 jumped more than 5.5 per cent in the wake of Pfizer’s announcement, adding £82 billion to the value of its shares in the market’s best day since March.

About 12 Covid-19 vaccines around the world are currently in the final stages of large-scale testing, but Pfizer is the first to report any results.

“We feel like we are on the cusp of one of the biggest medical advances for society and mankind in a 100 years that have passed here,” said Mikael Dolsten, the company’s chief scientific officer.

He added that there were tears of joy and celebrations in Pfizer’s Connecticut office following announcement of the interim data.

Professor David Nabarro, the WHO special envoy on Covid-19, has meanwhile called for caution, saying there there it still some way to go in the pandemic.

“Everybody who’s hearing and watching this will be saying ‘wow, does this mean that life can go back to normal in the near future?’ Life will go back to a new normal, and we’re not there yet,” he told the BBC.

“Even if a vaccine arrives in the near future we’ve got many months of still dealing with the virus as a constant threat that we’ve got to make certain that we continue to do all that is necessary to solve the virus causing major problems.

“The vaccine will help, but it’s not going to be a complete game changer.”

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