THE UK could see 50,000 new coronavirus cases a day by mid-October without further restrictions, the UK Government's chief scientific adviser has warned as he announced that small amounts of a vaccine could be available by the end of the year.

Sir Patrick Vallance said the 50,000 number "would be expected to lead to about 200 deaths per day" a month after that.

The briefing at Downing St comes as Prime Minister Boris Johnson considers whether to introduce further measures in England.

On Sunday, a further 3,899 daily cases and 18 deaths were reported in the UK.

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Speaking alongside the government's chief medical adviser, Prof Chris Whitty, Sir Patrick said: "At the moment we think the epidemic is doubling roughly every seven days.

"If, and that's quite a big if, but if that continues unabated and this grows doubling every seven days... if that continued you would end up with something like 50,000 cases in the middle of October per day.

"50,000 cases per day would be expected to lead a month later, so the middle of November say, to 200-plus deaths per day.

"The challenge therefore is to make sure the doubling time does not stay at seven days."

Towards the end of his statement Sir Patrick said small quantities of a vaccine to prevent could be available later this year.

"I am pleased to say good progress is being made. Many vaccines now have shown they generate an immune response of a type that ought to be protective and several vaccines are in very late stages of clinical testing aiming to show they are both effective and safe," he said.

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Sir Patrick went on to say that the UK through the vaccines taskforce has accessed to a number of the vaccines.

He added: "We don't yet know whether they will work but there is increasing evidence that points in the right direction and it's possible that some vaccine could be available before the end of the year in small amounts for certain groups.

"Much more likely that we'll see things becoming available over the first half of next year…In the meantime we have got to get in control of this," he said.