The deal involves an additional 60 million Moderna shots and 54 million Pfizer doses for next year and 2023, and will also include access to any modified vaccinations if they are needed to combat the Omicron strain or any other variant, the British health ministry said.
"These new deals will future proof 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," health minister Sajid Javid said.
So far, nearly 51 million people in Britain have received their first COVID vaccine - almost 89% of the population aged over 12, more than 46 million have had two doses, and some 18.6 million have received a booster shot.
On Tuesday Prime Minister Boris Johnson announced a new target this week to offer all adults a vaccine booster by the end of January, which means speeding up the rollout by an extra million doses a week.
So far 32 cases of the heavily mutated Omicron variant, which it is feared could be more transmissible, have been identified in Britain which has sparked the government into ramping out the vaccine programme.
Britain has made it mandatory to wear masks on public transport and shops, but Johnson and his ministers hope the booster programme will mean there will be no need for further restrictions or measures to curb social gatherings.
The contracts for the additional vaccines come on top of an order for 35 million Pfizer shots made in August for the second half of next year, and for 60 million Novavax and 7.5 million GlaxoSmithKline (GSK)/Sanofi doses which are due in 2022 but are yet to be approved by the British regulator.
Wealthy countries have been accused of not doing enough to distribute stockpiles of vaccines to poorer nations, and the British government said it remained committed to donating 100 million doses by the middle of 2022, saying 30 million would be donated by the end of this year.
Johnson will also on Thursday host a roundtable of leaders from major pharmaceutical firms including AstraZeneca, GSK and Pfizer to discuss preparations to deal with any future pandemics.
(Reporting by Michael Holden; editing by David Evans)
By Michael Holden