A big surge in vaccination capacity will be required if the UK is to succeed in tackling the new Omicron variant of coronavirus, Boris Johnson has said.
The prime minister said the NHS will "throw everything" at efforts to expand the booster jab programme to improve the immunity of Britons, amid concerns that the new Covid variant could be more dangerous than previous mutations.
Speaking on a visit to a GP surgery in North London, the PM said a "huge amount of progress" had been made against the Delta variant of coronavirus, but he said "we now have this question about the Omicron variant".
"What we need to do is delay the seeding of Omicron in this country... but we don't see any need to change the overall guidance for how people should be living their lives," he said.
The wearing of masks is once again being enforced in England in order to mitigate the impacts of the variant and the booster jab scheme has been extended so that all those aged over 18 are now eligible - those aged 12 to 15 have also been told they can now have their second dose. However, bookings for these have not yet opened.
And the recommended delay between second dose and third dose has been halved from six months to three months, meaning the number of people eligible has now doubled.
The NHS is administering around 350,000 booster jabs a day, according to official figures, but that figure will need to increase dramatically if the government wants to use third doses to drive up immunity in eligible people.
Vaccine capacity will need to see "another great surge", the PM said when speaking to the media.
"Is it going to be hard work? Yes, it is. But I know that people can do it".
The PM said there was "doubt about what exactly that variant (Omicron) can do" but boosters would give "a lot of protection against all types of the virus".
He said he would be getting his booster jab later this week and urged others to do the same, "because we think it's overwhelmingly likely that the booster, getting vaccinated, will give you more protection".
The PM said scientists at Porton Down are assessing the transmissibility of the new variant and how much vaccines can protect against it.
But, he said, "we don't see any need at present, certainly, to change the overall guidance about how people should be living their lives".
He added: "People should continue to do things like make sure they have lots of fresh air, they wash their hands and take normal precautions, I think that's entirely reasonable.
"But we're not going to change the overall guidance. We don't think that's necessary."