The vaccine was given the green light by the Medicines and Healthcare products Regulatory Agency (MHRA) just weeks after the Pfizer-BioNTech jab was passed. Dr June Raine, head of the MHRA, said “no corners have been cut” in assessing the safety and effectiveness of the vaccine was developed by scientists at the University of Oxford.
The UK has ordered 100 million doses of the Oxford University vaccine, enough to vaccinate 50 million people.
Boris Johnson said the development represented “a triumph” for British science, adding: “We will now move to vaccinate as many people as quickly as possible.”
And Health Secretary Matt Hancock called the latest development a “great British success story”.
He said “hundreds of thousands” of doses would be available for rollout next week, including to care homes.
The first jab is expected to be given as early as Monday.
Mr Hancock told Sky News: “I am now, with this approval this morning, highly confident that we can get enough vulnerable people vaccinated by the spring that we can now see the route out of this pandemic.”
He said there would be a difficult few weeks ahead but the “vaccine provides that route out” of the pandemic.
He added: “We have all just got to hold our nerve over the weeks to come.”
Since the rollout of the Pfizer-BioNTech vaccine this month, more than 600,000 Britons have been vaccinated.
READ MORE: Coronavirus update: Pregnant women now permitted Pfizer-BioNTech jab
The announcement comes amid increasing strain on hospitals in England, where the number of COVID-19 patients is the highest it has been during the pandemic.
As of 8am on Monday there were 20,426 Covid patients in hospitals, NHS England said.
This compares to 18,974 on April 12, the spring height of the pandemic.
The MHRA’s approval of the Oxford vaccine came just a day after the UK saw a new record high of coronavirus cases.
On Tuesday 53,135 fresh infections were declared, marking the first time the daily figure rose above 50,000.
Mr Hancock is due to announce any changes to tier areas in a statement to the Commons on Wednesday.
He told Sky News: “We are facing a very significant challenge in the NHS right now.
“There has been a significant rise in the number of cases – the highest number of cases recorded yesterday, 53,000 cases.
“We are going to have to take further action.”