Britain has bought enough vaccines for two more boosters per person, under a deal to provide 114 million more jabs that can be modified against new variants.
Ministers said the deal with Moderna and Pfizer, covering two more years, would “futureproof” the country beyond this winter’s rollout.
Health chiefs are scrambling to accelerate the current programme so all eligible adults can be offered a third jab by the end of January, in an attempt to protect people from the omicron variant.
Nine more cases of the variant were identified in England on Wednesday, taking the total number of confirmed UK cases to 32. Work is under way to establish if there are links to travel to southern Africa, with health officials warning that more cases are “very likely”.
On Wednesday, an Israeli cardiologist identified as one of the first people in the world to be infected with omicron said he believed he caught it while in London last month, attending a heart conference attended by more than 1,200 medics.
The disclosure raised concerns that the variant arrived in this country earlier than was known, with fears it could have spread at the event at ExCeL London more than a week ago.
On Wednesday, daily reported cases of coronavirus doubled in South Africa, rising to 8,561. The omicron variant has been found to account for three-quarters of virus genomes sequenced in the country since it was identified last month.
NHS England is in the process of drawing up new guidance, setting out how the accelerated rollout of boosters in this country will work.
On Wednesday, the NHS had yet to issue plans for an accelerated rollout of jabs, four days after the Prime Minister called for a rapid extension of boosters.
The plans are expected to see a sharp increase in the number of hospitals offering jabs to the public. Currently, just 30 NHS hospitals in England offer boosters.
But this number is expected to double in the next two weeks, while all 230 NHS trusts in England will be asked if they can run such clinics.
On Monday, the Joint Committee of Vaccination and Immunisation recommended that the gap between doses could be cut to as little as three months. However NHS chiefs have yet to announce a plan, amid wrangles with GPs over how the workload will be managed.
Despite several days of talks, GPs have said they can only take on an expanded role if they stop providing millions of routine health checks.
The new guidance is expected to say that the accelerated rollout - which cuts the gap between second and third dose to a minimum of three months, rather than six - should start by December 13 at the latest.
Those aged in their 40s and 50s who have yet to receive their third jab will be in the first group called forward.
Meanwhile Ursula von der Leyen, president of the European Commission, called on EU member states to consider making Covid vaccinations mandatory, while the World Health Organisation reported that the variant had so far been found in 23 countries.
In this country, health officials are attempting to draw up plans to administer boosters to more than 25 million people aged 18 and over in two months.
Ministers signalled that the plan could mean fewer GP appointments for other reasons, with family doctors told that there was “nothing more important” than the national rollout.
Sajid Javid: Covid booster rollout is a ‘national mission’
The Health and Social Care Secretary said a new deal for 114 million doses of Moderna and Pfizer in 2022 and 2023 would help to protect the public “for years to come”.
The deal includes 60 million additional doses of the Moderna vaccine and 54 million more Pfizer/BioNTech doses. Officials said the Government already had enough supply of both Moderna and Pfizer/BioNTech for the current booster programme.
The Pfizer and Moderna vaccines were preferred to AstraZeneca because they are mRNA jabs that are thought to adapt better to variants.
Officials said the new contracts, accelerated in the light of the new variant, include “access to modified vaccines” in case needed to combat omicron and future variants of concern.
Sajid Javid said: “Thanks to the Vaccines Taskforce, we have an excellent track record of securing the vaccines the country needs to keep this virus at bay.
“These new deals will futureproof the Great British vaccination effort – which has so far delivered more than 115 million first, second and booster jabs across the UK – and will ensure we can protect even more people in the years ahead.
“This is a national mission and our best weapon to deal with this virus and its variants is to get jabs in arms – so when you are called forward, get the jab and get boosted.”
On Thursday, the Prime Minister will convene a summit of scientists and leaders of the pharmaceutical industry, as part of efforts to tackle emerging variants and create “variant-proof” vaccines within 100 days.
Boris Johnson said he was “bringing global industry leaders together to discuss our renewed efforts against Covid-19, while ensuring we are better equipped to tackle future healthcare challenges”.
However, global health leaders have questioned the UK’s booster campaign.
Dr Mike Ryan, executive director of the World Health Organisation's health emergencies programme, said the focus should be on ensuring the global population receives a first dose.
He told a press briefing: “Right now, there is no evidence that I'm aware of that would suggest that boosting the entire population is going to necessarily provide any greater protection for otherwise healthy individuals against hospitalisation or death.”
Plans to increase pace of jab rollout
In total, the Government has secured early access to 453.5 million vaccine doses through supply agreements with six separate vaccine developers. These include 70 million that are being donated to other countries and 67 million doses of vaccines that have yet to be regulated.