Brown, who is a United Nations special envoy, called on US President Joe Biden and other Group of Seven leaders to urgently ship vaccines from warehouses in America and Europe to Africa.
Western countries are hoarding nearly 300 million shots while only 70 million people in Africa have so far been vaccinated, Brown said in an opinion piece published in The Sunday Mirror, citing research by data firm Airfinity.
By Christmas, the West is set to have one billion surplus doses even if every European and American adult has received a booster shot and all children over 12 are injected, he added.
“We are in a new ‘arms’ race – to get vaccines into people as quickly as possible – but this is an arms race where the West have a stranglehold on the vaccine supplies,” Brown stated.
The grip of rich countries on vaccine stocks was stopping Covax, the international facility for buying vaccines, from meeting its promise to send two billion vaccines to poorer countries this year, he added.
The stockpiling has also delayed dose-sharing by G7 countries with Africa and low-income countries, Brown said.
His remarks came as around half a million people in the UK are to be offered a third jab.
Last month, the Biden administration also announced a plan to offer booster shots to all Americans.
The World Health Organization (WHO) condemned the rush by the wealthy countries to provide booster shots, comparing the move to providing “extra life jackets to people who already have life jackets, while we’re leaving other people to drown without a single life jacket”.
Biden, however, defended the plan by claiming that the US has donated more vaccine doses than the rest of the world combined.