People will be likely to need to have annual Covid vaccinations for many years to come, the head of Pfizer has told the BBC
Dr Albert Bourla said he thought this would be needed to maintain a "very high level of protection".
The UK has now secured an extra 114 million doses of Pfizer and Moderna vaccines to be delivered over the next two years.
A year ago the UK was the first country to approve the Pfizer-BioNTech vaccine.
Pfizer's chief executive was speaking to the BBC before the emergence of the Omicron variant, first identified in South Africa and also before the announcement that the UK government had signed contracts to buy the 54 million additional Pfizer-BioNTech and 60 million Moderna doses for 2022 and 2023.
These deals include access to modified vaccines if needed to combat Omicron and future variants of concern, the Department of Health has said.
Dr Bourla said Pfizer had already made updated vaccines in response to the Beta, also first identified in South Africa, and Delta, first identified in India, variants but that they had not been needed.
The company is now working on an updated jab in response to the Omicron variant that could be ready in 100 days.
He said vaccines had helped save millions of lives during the pandemic, and without them the "fundamental structure of our society would be threatened"
By the end of the year Pfizer expects to have supplied three billion doses of its messenger ribonucleic-acid (mRNA) vaccine with four billion planned for next year.
There had been a global race to protect people protected, Dr Bourla said, but in 2022, countries would have "as many doses as they need".
