Prime Minister Boris Johnson says he is "absolutely convinced" that the UK will have a vaccine within "a few months".
Speaking at a Downing Street press conference, he said: "In just a few months we will have a vaccine. I'm absolutely convinced of it now.
"And I'm convinced ... that by April things genuinely will be much much better."
But the Prime Minister insisted that the tough new lockdown rules planned for regions such as the North East are the only way of avoiding another full national lockdown early next year, before a vaccine has been widely distributed.
He said: "If we ease off now, we risk losing control of this virus all over again, casting aside our hard won gains and forcing us back into a New Year national lockdown."
Mr Johnson spoke hours after the Government confirmed details of a new three-tier local lockdown system.
The entire North East will be in "tier three" once the national lockdown ends on December 2 and new regional lockdowns begin..
But Mr Johnson said the rules could be changed to allow people to meet friends and family if they tested negative for coronavirus even if they were in a "tier three" area with heavy restrictions.
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The Prime Minister said wanted to expand the mass testing regime which has already been introduced in Liverpool.
"This is a success story which we want other parts of the country to replicate."
He added: "Testing on this scale is untried. But in due course, if it works, where people test negative, it may also be possible for families and communities to be released from certain restrictions even if their home area stays in tier three."
From Wednesday, most of England will be in one of the top two tiers of the three-tier system - which means hospitality businesses, including pubs and restaurants, are either forced to close or face a massive drop in custom.
Also taking part in the press conference were Chris Whitty, England's Chief Medical Officer, and Sir Patrick Vallance, the Government's Chief Scientific Adviser.
