Mr Brown, who has been appointed an ambassador for global health financing by the World Health Organisation (WHO), has been campaigning tirelessly in recent months for wealthy nations and the private sector to ensure the equitable distribution of Covid-19 vaccines.
He is calling for a concerted global effort to save lives, especially in poorer countries, to help end the pandemic and restore livelihoods the world over.
He told Sky News that only 2% of Africa and only 2% of low-income countries are vaccinated and called for unused vaccines to be distributed where they are needed.
There are still millions of vaccines left over and we've got to get them to the rest of the world
He told the broadcaster: “It’s in our interests in Britain that they are vaccinated because the disease will spread in Africa, it will mutate and there will be new variants, it will come back to haunt even the fully vaccinated in Britain unless we take action.
“We’ve been stockpiling vaccines, we’ve got a mountain of vaccines in America and in Europe, they’re not going to be used even when we do the boosters and the 12 to 15-year-olds. There are still millions of vaccines left over and we’ve got to get them to the rest of the world, otherwise they are going to pass their use-by date and expire, and be of no use to anybody, and all of us hate waste.”
He added: “My plan is that this month we could transfer 300 million vaccines, that’s from America and Europe, by next month it could be 500 million and by December a billion, and so we need to get all the resources at our disposal to airlift them to get them out to the countries that need them, get the vaccinations happening and provide some support.”
Mr Brown said he fears that unless this action is taken then Africa could become the “centre for Covid” and “if in future you have new variants and mutations coming out of Africa, then it really will hurt the rest of the world”.
The former prime minister said he believed the entire world could be vaccinated by next summer, if developed nations help in the rollout elsewhere.
He told BBC Scotland’s Good Morning Scotland programme: “I believe that the whole world, all those adults who want a vaccination and we can get the vaccination to, can be vaccinated by next summer.”
He said: “I believe that the plan that President Biden and others should agree, is that by December we get 40% of the world vaccinated, that’s of the poorest countries, then by next spring we are up to 70%.
“That’s the figure that people have settled on for the rest of the world – that’s on top, of course, of the rich countries, our countries, already having 70% or more fully vaccinated at the moment.”
He added: “Forty per cent by December, 70% by May and everybody will be safer as a result.”
Commenting on Mr Brown’s new role, Dr Tedros Adhanom Ghebreyesus, WHO director-general, said: “I am delighted and honoured that Gordon Brown has agreed to serve as WHO ambassador for global health financing.
“In this role, he will elevate and support the WHO’s work to raise awareness internationally on the great need for sustained global health financing, particularly from G20 and G7 countries.
“As a long-time friend of Gordon’s, I know that he will bring his sharp intellect, firm commitment and deep sense of justice to this ambassadorship.”