BORIS Johnson has brought forward the target for giving every adult in England a booster jab by a month over fears of a “tidal wave of Omicron” that could cause “very many deaths”.

The Prime Minister, in a pre-recorded address, said Britain “must urgently reinforce our wall of vaccine protection” as he set a new deadline of jabbing everyone over 18 by the new year.

He said scientists had discovered that being fully vaccinated is “simply not enough” to prevent the spread of the coronavirus mutation and that, without a lightning speed mass booster campaign, the NHS could be overwhelmed.

The mission to administer millions more jabs by December 31 will see 42 military planning teams deployed across every health region.

Extra vaccine sites will be opened and additional mobile units deployed, clinic opening hours are to be extended to allow people to be jabbed around the clock and at weekends, while thousands more vaccinators will be trained.

First Minister Nicola Sturgeon said Scotland would match the aim of offering boosters to all eligible adults before 2022, but added that more Covid-19 restrictions may still be needed to tackle the new strain.

Welsh leader Mark Drakeford also said “further steps” could be required to keep the country safe, as he encouraged people to “make having your booster a priority” amid a pledge to quicken the rollout.

The announcement comes as the UK Covid alert level was raised to Level 4, up from Level 3, following a rapid increase in the number of Omicron cases being recorded.

The recommendation was made to ministers by the country’s four chief medical officers and NHS England’s national medical director following advice from the UK Health Security Agency (UKHSA).

Scotland’s chief medical officer Gregor Smith joined his counterparts in England, Wales and Northern Ireland in recommending the increase.

In a joint statement, they 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 UK, as of Sunday, recorded a further 1239 confirmed cases of the Omicron mutation, bringing the total number of cases to 3,137 – a 65% increase from Saturday’s total of 1898.

Education Secretary Nadhim Zahawi said the actual number was likely to be 10 times as high.

The Prime Minister said: “We’ve already seen hospitalisations doubling in a week in South Africa and we have patients with Omicron here in the UK right now.

“At this point our scientists cannot say that Omicron is less severe.

“And even if that proved to be true we already know it is so much more transmissible that a wave of Omicron through a population that was not boosted would risk a level of hospitalisation that could overwhelm our NHS and lead sadly to very many deaths.

“So we must act now. Today we are launching the Omicron emergency booster national mission, unlike anything we’ve done before in the vaccination programme, to get boosted now.

“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’m 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 Prime Minister – whose address was pre-recorded, meaning he spoke to the nation without being flanked by his scientific advisers and without taking questions from the media – said the UK Government would support the devolved administrations to “accelerate” their own rollouts of third jabs.

During his address, the Prime Minister revealed that the decision to speed up the jab rate in England would mean some NHS appointments would need to be postponed until the new year, arguing there would be “even greater” cancellations if the wave of Omicron infections was allowed to swell.

In a direct plea to GPs, doctors, nurses and others on the NHS front line, who he said had “worked incredibly hard” throughout the pandemic, Johnson said: “I must ask you to make another extraordinary effort now, so we can protect you, and your colleagues, and above all protect your patients from even greater pressures next year.”

Labour leader Sir Keir Starmer said the Government had his party’s support to accelerate the booster programme, as he urged the public to “protect our families, friends and the NHS” by getting a top-up jab.

NHS England said the turbo-charged effort would be the “biggest and fastest vaccine programme in health service history”.

Chief executive Amanda Pritchard said Omicron poses a “grave” threat that could lead to a new wave of infections “even greater than those that have gone before”.

She said the NHS would do “everything in our power to rise to this extraordinary challenge”.

The online booster booking system – which appeared to be experiencing technical difficulties shortly after the Prime Minister’s televised address – would be “shortly open to all adults”, said Pritchard, adding: “Please don’t hesitate with your booking and get boosted now.”