Pharmaceutical firm Pfizer has announced that its Covid-19 vaccine is more than 90% effective in preventing the disease.
A coronavirus vaccine is seen as essential if restrictions on people’s lives are ever to be fully lifted.
The firm, which is developing the vaccine with BioNTech, said the results were from independent interim analysis of a clinical study.
Pfizer hailed the announcement as a “great day for humanity” and said it believes it will be able to supply 50m doses by the end of this year, and around 1.3bn by the end of 2021.
The UK has already ordered 40m doses – with each person needing two jabs – and it’s expected that frontline health workers and vulnerable people would be first in line.
More than 43,500 people took part in the study – 42% from diverse backgrounds – and no serious safety concerns were found, the companies said.
Researchers said protection is achieved 28 days after the vaccine – which consists of two doses – is taken. However, there remain questions about how long immunity lasts.
In a statement released on Monday, Pfizer’s chairman said it was “a great day for science and humanity”.
Dr Albert Bourla, Pfizer chairman and CEO, said: “We are reaching this critical milestone in our vaccine development programme at a time when the world needs it most with infection rates setting new records, hospitals nearing over-capacity and economies struggling to reopen.
“With today’s news, we are a significant step closer to providing people around the world with a much-needed breakthrough to help bring an end to this global health crisis.”
Scotland’s First Minister Nicola Sturgeon welcomed the “good news” at her daily update.
She described the development as being “perhaps amongst the best news we’ve had in recent weeks”.
Sturgeon said: “It’s not going to provide us with a way out of this today, or tomorrow, or next week, or perhaps not even in this calendar year.
“But that development … does give us right now real hope that in the not too distant future science is going find us the way out of this terrible time.”
Peter Horby, professor of emerging infectious diseases and global health at Oxford University, said the Pfizer results “bode well for Covid vaccines in general”.
“This news made me smile from ear to ear,” said the scientist. “It is a relief to see such positive results on this vaccine and bodes well for Covid-19 vaccines in general.
“Of course we need to see more detail and await the final results, and there is a long long way to go before vaccines will start to make a real difference, but this feels to me like a watershed moment.”