Top scientists raised the Covid alert level from three to four this afternoon, following a rapid increase in the number of infections caused by the new strain in recent days.
More than 1,200 new cases of Omicron were added to the nationwide tally on Sunday, taking the total to 3,137, a 65% increase from Saturday’s total of 1,898 UK cases.
Meanwhile, it has also been reported that there are now patients with the Omicron variant being treated in hospital.
In a rare televised address this evening, Mr Johnson said that Britain is now “facing an emergency in our battle with the new variant” and that jab eligibility will now be rushed forward to “reinforce our wall of vaccine protection,”
Launching the so-called ‘Omicron Emergency Boost’, Mr Johnson said: “No-one should be in any doubt: there is a tidal wave of Omicron coming.”
“It is now clear that two doses of vaccine are simply not enough to give the level of protection we all need,” he added.
The Prime Minister went on: “A fortnight ago I said we would offer every eligible adult a booster by the end of January.
“Today, in light of this Omicron Emergency, I am bringing that target forward by a whole month.
“Everyone eligible aged 18 and over in England will have the chance to get their booster before the New Year.”
The online booking system will be open to everybody over the age of 18 by Wednesday, and following on from suggestions that Omicron may be milder than earlier versions of the virus, Mr Johnson added: “Do not make the mistake of thinking Omicron can’t hurt you; can’t make you and your loved ones seriously ill.”
Mr Johnson admitted that in order to achieve the accelerated target, other scheduled appointments will need to be pushed back until January, but by not doing so, “the wave of Omicron could be so big that cancellations and disruptions, like the loss of cancer appointments, would be even greater next year.”
The country’s four chief medical officers and NHS England’s national medical director have recommended to ministers that the UK go up to Covid Alert Level 4 from its previous Level 3.
This means the epidemic is “in general circulation, transmission is high and direct Covid-19 pressure on healthcare services is widespread and substantial or rising”, according to Government guidance.
In a joint statement, the CMOs and NHS England’s Professor Stephen Powis said the emergence of Omicron “adds additional and rapidly increasing risk to the public and healthcare services”.
They added: “Early evidence shows that Omicron is spreading much faster than Delta and that vaccine protection against symptomatic disease from Omicron is reduced.
“Data on severity will become clearer over the coming weeks but hospitalisations from Omicron are already occurring and these are likely to increase rapidly.”
The interventions come after one top scientist warned that more restrictions could be needed in order to stem the increase in cases, and that the Government has some “very difficult” decisions ahead.
Dr Susan Hopkins, the chief medical adviser for the UK Health Security Agency urged people to reduce their social contacts ahead of the Christmas break.
“I think that the restrictions that the Government have announced are sensible. I think that we may need to go beyond them. But we’ll need to watch carefully what happens with hospitalisations,” she told the BBC.
Sunday saw another a further 48,854 lab-confirmed Covid-19 cases in the UK, alongside another 52 confirmed fatalities.