For many of the countries receiving this welcome donation of vaccines, such an extraordinary effort will be a potential game-changer in helping them emerge from the pandemic.

According to multiple news reports, the United States has purchased and will subsequently donate an astounding 500 million doses of Pfizer’s highly effective Covid-19 vaccine worldwide as America seeks to be a key player in getting other nations vaccinated, particularly lower-income nations.

President Joe Biden will announce the news at the G7 summit in Cornwall, England, later today (Thursday, June 10). 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 with the plan said.

The US government will pay for the vaccines from Pfizer at what is said to be a ‘not-for-profit’ price, and Pfizer CEO Albert Bourla is expected to appear with President Biden when he announces the initiative.

The distribution of half a billion vaccine doses has the potential to be a significant milestone in the global effort to put an end to a pandemic that has claimed nearly four million lives and disrupted lives and livelihoods throughout the world for nearly a year and a half.

The doses will be distributed through the global COVAX programme and will benefit 92 countries worldwide, along with the African Union, which comprises 55 countries.

The US had initially committed to donating 60 million doses, then recently raised that to 80 million. Those doses will be shipped out this month. The new programme to buy and donate 500 million doses is on top of the 80 million already confirmed.

Many public health experts and advocacy groups cheered the news of the White House’s deal with Pfizer, saying America’s leadership on the issue will be critical to vaccinating the world.

“It’s an extraordinary development,” said Jennifer Nuzzo, an epidemiologist and senior scholar at the Johns Hopkins Center for Health Security, adding that the announcement “sends a profound signal in terms of US commitment to global health security and willingness to help end this pandemic for the world and the United States.”

According to The Washington Post, following the news of President Biden’s forthcoming announcement, international health organisations are now calling on other wealthy countries to increase their own global commitments, warning about the need to halt the contagion around the world to prevent more dangerous variants from spreading.

“We won’t end this global pandemic anywhere unless we beat it everywhere,” Tom Hart, acting CEO of the One Campaign, an organisation focused on fighting global poverty and preventable disease, said in a statement. “Donating doses to COVAX will save lives, reduce the spread of variants, and help reopen the global economy. We urge other G7 countries to follow the US’ example and donate more doses to COVAX. If there was ever a time for global ambition and action to end the pandemic, it’s now.”

Reports from The Washington Post, CNN, BBC, and Channel News Asia contributed to this article.