A VACCINE being fast-tracked by Oxford University's Jenner Insititute has an 80 percent chance of success, provided the Government steps in to help accelerate its manufacture, a scientist leading the groundbreaking project has said.

Clinical trials on the ChAdOx1 nCoV-19 vaccine are about to get underway - and Professor Sarah Gilbert said she remained confident, despite by comments by Sir Patrick Vallance, the UK's chief science officer, suggesting all such treatments were "long shots". 

Speaking on BBC's Andrew Marr show, she said: "What we need from Government is support to help us accelerate the manufacturing. "There aren't any manufacturing facilities in this country that at the moment can make very large amounts of the vaccine.

"We have always said this will not be the only vaccine.

"We think multiple vaccines can be successful, but there now I think about 140 different vaccines in development and not all of them will be successful by any means."

Prof Gilbert's comments built on her remarks last week, when she said she thought the treatment had an 80 per cent chance of working.

She added: "Personally, I have a high degree of confidence.

"This is my view, because I've worked with this technology a lot, and I've worked on the MERS vaccine trials, and I've seen what that can do."

Her comments followed those of Sir Patrick, writing in The Guardian, who said of a possible vaccine.

"Ideally, we would have one ready to take off the shelf and roll out yesterday. One that could be delivered at scale.

"Work must and will be taking place to build the manufacturing capacity needed to take any vaccine from lab to jab; producing the millions or potentially billions of doses that will be needed.

"This sort of scaling of a vaccine can be done but is not a trivial task."

He added: "All new vaccines that come into development are long shots.

"Only some end up being successful, and the whole process requires experimentation."

Merck, a Germany-based science and technology company, and The Jenner Institute last week announced plans for large-scale production of ChAdOx1 nCoV-19, with more than 500 people already signed up for trials which are likely to start towards the end of this week.

Udit Batra, a member of the Merck Executive Board and CEO, Life Science, said: “We have brought the future of vaccine manufacturing to the present.

“This is an important step in treating COVID-19 and other diseases that impact global public health.

"This work marks a milestone in the vaccine manufacturing development journey, as clinical testing continues to advance.”

The beginning of the study would mean the UK is just one of three countries - alongside China and the USA - to have started clinical trials of a COVID-19 vaccine.

Speaking to Sky News's Sophy Ridge yesterday, Sir Jeremy Farrar, a member of the Government's Scientific Advisory Group for Emergencies (Sage) said: "I hope we would have a vaccine towards the end of this year - but that's a vaccine in a vial, it's a vaccine that we believe to be safe, a vaccine we think might be effective.

"I think it's crucial to realise having a vaccine in itself, in say a million doses, which you know to be safe and you believe to be effective. That is not the end game.

"The end game is making sure that it is truly effective."