Photo: AFP / FILE
US President Joe Biden, in the UK for a G7 summit, said on Thursday that this would be the largest single purchase and donation of Covid-19 vaccines by any single country ever .
He vowed the US would be the arsenal of vaccines in our fight against Covid .
Speaking alongside him, Pfizer chief executive Albert Bourla said he could see a light at the end of the tunnel .
The 500 million sounds like a lot - but what difference will it make?
What has the US promised?
It has agreed to purchase the doses from Pfizer at a not for profit price.
The U.S. will buy 500 million more doses of the Pfizer COVID-19 vaccine to share through the global COVAX alliance for donation to 92 lower income countries and the African Union over the next year, a person familiar with the matter said Wednesday.