The Government's Chief Scientific Adviser Sir Patrick Vallance has said "there’s been great progress made" in producing a coronavirus vaccine.
Scientists across the world are working on creating a vaccine, with optimism increasing that there will be one available in the future.
Trials have already begun on workable vaccines but testing such items does take time in order to prove it works.
"You can never guarantee there will be a vaccine, it's a tough thing to do," Sir Patrick said.
"I will say there's been great progress made, though.
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"There's been a number of vaccine programmes around the world, which are progressing.
"There's a number in the clinic now ... so far so good.
"The chances are a bit higher than they were of getting a vaccine, but you never know until you've got one."
In addition to a potential vaccine, there are also therapeutic methods being worked on, he said.
Speaking alongside Sir Patrick, Chief Medical Officer Professor Chris Whitty said he was confident a solution would be found.
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Boris Johnson said there was no guarantee that there could be a vaccine for Covid-19, but was hopeful the UK was at the forefront of developing one.
“I’m hearing some very encouraging things from what’s going on at Oxford to achieve a vaccine,” he said at the Downing Street briefing.
But he added: “This is by no means guaranteed.
“I believe I’m right in saying that even after 18 years we still don’t have a vaccine for Sars.
“What I can tell you is that the UK is at the forefront of concerting international activity to try to deliver a vaccine.”
He said the government was putting “huge sums” into finding a vaccine, but added: “If you ask me am I absolutely certain that we won’t be living with this for a long time to come, I can’t say that.
“It may be that we have to become ever more flexible, ever more agile, ever smarter in the way that we tackle, not just this infection, but potentially future infections as well.”
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