The Government is investing a further £84 million in the hunt for a coronavirus vaccine as ministers announced a ground-breaking deal which could make millions of doses available in the UK as early as September.

Business Secretary Alok Sharma said the additional funding would support teams at Oxford University and Imperial College London engaged in the global race to find a vaccine that could finally end the devastating pandemic.

At the same time, he said Oxford had signed a global licensing agreement with AstraZeneca which could see it supply 100 million doses of a vaccine – with 30 million going to the UK – as soon as September if one has been found by then.

“The UK will be first to get access but we can also ensure that in addition to supporting people here in the UK we’re able to make the vaccine available to developing countries at the lowest possible cost,” he told the daily No 10 press briefing.

While the announcement will be seen as a boost to hopes of finding a vaccine, Boris Johnson earlier cautioned that there was still a lot to do and that the search may never be successful.

Writing in The Mail on Sunday, he said: “There remains a very long way to go, and I must be frank that a vaccine might not come to fruition.”

Mr Sharma said, however, that trials of the Oxford vaccine were “progressing well” with the phase one participants having received their doses earlier this week.

“The speed at which Oxford University has designed and organised these complex trials is genuinely unprecedented,” he said.

He said the additional research funding would help with the mass production of the vaccine so that if trials are successful “we have dosages to start vaccinating the UK population straight away”.

In a further move, he said that the Government was putting in £93 million to accelerate the completion of the UK’s first vaccines manufacturing innovation centre.

The facility at Harwell in Oxfordshire – which is already under construction – is now expected to open in summer 2021, a year ahead of schedule.

Mr Sharma said that once it was operating it would have the capacity to produce enough vaccine doses to serve the entire UK population in as little as six months.

In the event that a vaccine was found before then, he said the Government was providing £38 million to build a “rapid deployment facility” which will be able to start manufacturing “at scale” from this summer.

“The UK continues to lead the global response to find a vaccine, and the Government is backing our scientists to do this as quickly as possible,” he said.

However if the search for a vaccine was not successful, he said they were also looking at other drug treatments and therapeutics, with six drugs having entered initial live clinical trials.

The announcements came as the latest Department of Health figures showed 34,636 people had died in hospitals, care homes and the wider community after testing positive for coronavirus in the UK as of 5pm on Saturday, up by 170 from the day before.

Earlier, senior Cabinet minister Michael Gove said the Government was on track to meet its target of getting 18,000 contact tracers by next week with 17,200 now recruited.

As a result, he said the coronavirus test, track and trace programme – seen as key to further lifting the lockdown restrictions – would be up and running by the end of month.

Mr Gove also issued a fresh appeal to councils and teaching unions opposed to the Government’s plans to begin reopening primary schools in England from June 1 to think again.

He said measures were being put in place to ensure the safety of children and staff – including limiting class sizes to 15 – although he acknowledged they could not eliminate all risk.

“There is always, always, always in any loosening of these restrictions a risk of people catching the coronavirus,” he told the BBC’s The Andrew Marr Show.

“The key thing is that we can make these workplaces safe. You can never eliminate risk, but as we know, it is the case that it’s extremely unlikely that any school is likely to be the source of a Covid outbreak.

“If for any reason there are risks then we can take steps to mitigate them.”

Mr Gove said there are “big lessons” to be learned from the treatment of care homes during the outbreak amid growing criticism of the lack of Government support for the sector.

While “significant steps” had been taken to improve the situation, he said it remained a “challenge”.

“We are still living through this pandemic and there will be lessons to be learned,” he said.

“There will be a point in the future when all of us can look back and reflect and make sure we have learned the appropriate lessons.”