The Prime Minister said that despite positive developments in the race for a Covid-19 vaccine, the months ahead “will be hard, they will be cold, they include January and February when the NHS is under its greatest pressure”.
It came hours after the team behind the Oxford-AstraZeneca coronavirus vaccine said its jab is up to 90 per cent effective.
Mr Johnson, who is self-isolating, spoke via video-link at a Downing Street press conference with chief medical officer Professor Chris Whitty and Oxford Vaccine Group director Professor Andrew Pollard.
He warned that “this is not the moment to let the virus rip for the sake of Christmas parties”.
“Tis the season to be jolly, but it is also the season to be jolly careful, especially with elderly relatives.”
Asked about an agreement of rules for Christmas across the nations of the UK, Boris Johnson said: “We want people to be able to celebrate, but we don’t want to ruin it by overdoing it.â¨
“I think there’s a wide measure of agreement about that and I think you can probably expect some news about the way forward pretty soon.”
The Oxford vaccine results follows positive data from Pfizer and Moderna, but none of the jabs have yet been approved for use and getting people vaccinated will be a major undertaking.
The Prime Minister said: “We can hear the drumming hooves of the cavalry coming over the brow of the hill but they are not here yet.
“Even if all three vaccines are approved, even if the production timetables are met – and vaccines notoriously fall behind in their production timetables – it will be months before we can be sure we have inoculated everyone that needs a vaccine.”
Under the new system:
– In Tier 2, alcohol may only be served in hospitality settings as part of a substantial meal.
– In Tier 3, pubs and restaurants will only be able to offer takeaway and delivery services, while indoor entertainment, hotels and other accommodation will close.
The 10pm curfew will be relaxed, with last orders now closed at that time and premises ordered to shut at 11pm.
Details of which areas will be in which tiers will be set out on Thursday.
Mr Johnson said said that “things will look and feel very different” after Easter with a vaccine and mass testing.
But he stressed the months ahead “will be hard, they will be cold, they include January and February when the NHS is under its greatest pressure”.
Mr Johnson stressed that a vaccine would not be compulsory but said people should want to receive one.
He said: “There will be no compulsory vaccination, that’s not the way we do things in this country.
“We think it’s a good idea – I totally reject the propaganda of the anti-vaxxers; they are wrong – vulnerable people, people who need a vaccine should definitely get a vaccine.
“Everybody should get a vaccine as soon as it is available.”
England’s chief medical officer Professor Chris Whitty said: “My advice – any medical practitioner’s advice – would be these should be voluntary vaccinations.
“People should want to take them because they will protect them from a potentially very debilitating – and in some cases, sadly, fatal – disease."