The British government has secured coronavirus vaccines for possible booster campaigns over the next two years.
Some scientists have suggested that Covid-19 will need to be kept at bay with repeated vaccination campaigns while others say it is too early to tell whether annual boosters will be needed.
Health Secretary Sajid Javid said the deals “future-proof” the country’s vaccine programme.
They consist of 60 million more shots of the Moderna vaccine and 54 million Pfizer-BioNTech doses.
The Department of Health and Social Care said the deals included access to modified vaccines if they were needed to combat the Omicron strain and future variants of concern.
It said the new deals are in addition to 35 million additional doses of Pfizer-BioNTech's vaccine ordered in August for delivery in the second half of next year, and the 60 million Novavax and 7.5 million GSK-Sanofi doses.
The department said the government already had enough supply of Moderna and Pfizer-BioNTech for the expanded booster programme.
Officials announced that all adults in the UK would be offered a booster shot before the end of January amid growing concerns about the Omicron variant.
Vaccination experts advising the government have expressed preference for the mRNA vaccines – Pfizer and Moderna.
Trial data suggests booster doses are generally well tolerated and provide a substantial increase in vaccine-induced immune responses in particular, and that mRNA vaccines provide a strong booster effect.
“Thanks to the vaccines taskforce, we have an excellent track record of securing the vaccines the country needs to keep this virus at bay," Mr Javid 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.
“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.”
Global health leaders have questioned the UK’s booster campaign.
Dr Mike Ryan, executive director of the World Health Organisation's emergencies programme, said he was not aware of any evidence that would suggest offering booster shots to the entire population gives any greater protection to healthy people.
“It’s tough for some countries who have huge amounts of excess vaccine to decide who to give it to, but that’s not the problem being faced by a lot of countries around the world who can’t get even primary vaccination to their most vulnerable," Dr Ryan said.
"So it’s a luxurious position to be in if you’re in a position to be able to have enough vaccine to do that.”
“The primary objective, I think, of all governments now must be, in the face of Delta and Omicron and others, to ensure that all vulnerable individuals, people of older age, people with underlying conditions, are immediately offered the vaccine to ensure that everyone has had at least a primary course of vaccine.
“There are others here who can better answer than me regarding the benefits of a booster regarding other variants, but 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.
“The real risk of severe disease, hospitalisation and death lies in particularly at risk and vulnerable individuals who do require protection against all variants of Covid-19."