CNN

The US has purchased and will donate 500 million doses of Pfizer's Covid-19 vaccine worldwide as it seeks to be a key player in getting other nations vaccinated, a person familiar with the move told CNN.

President Joe Biden will announce the news at the G7 summit in Cornwall, England, this week, the person said.

Around 200 million doses will go out in 2021 and 300 million will be distributed in the first half of 2022. Biden's top Covid adviser, Jeff Zients, has been working on the deal for the last month, a person familiar said.

All doses will go through COVAX, the international vaccine initiative, and will go to 92 low- and lower-income countries, in addition to the African Union.