World leaders of the Group of Seven are expected to announce Friday a commitment to share 1 billion of their COVID-19 vaccine resources with lower-income countries struggling to control the spread of the virus.

On Thursday, President Biden announced plans for the U.S. to donate 500 million doses of the Pfizer COVID-19 vaccine globally. The first 200 million are expected to be distributed this year and the rest will follow in 2022.

"Our values call on us to do everything that we can to vaccinate the world against COVID-19," Biden said of the decision. "It's also in America's self-interest. As long as the virus rages elsewhere, there's a risk of new mutations that could threaten our people."

Canada, France, Germany, Italy, Japan, the United Kingdom and the U.S. make up the G-7.

The move by the wealthy democracies to share their vaccine stockpiles comes as relatively high vaccination levels in those countries have led to a decline in infections, hospitalizations and deaths. Enough improvements have been made in the U.S. and U.K. for coronavirus-related protocols to ease.

But in South Asia and Latin America, countries are still struggling to contain the virus.

In late May, the World Health Organization urged wealthier countries to contribute more to COVAX and requested at least 1 billion excess doses by the end of 2021. The COVAX program distributes mass quantities of vaccines to countries based on their populations.

"By donating vaccines to COVAX alongside domestic vaccination programmes, the most at-risk populations can be protected globally, which is instrumental to ending the acute phase of the pandemic, curbing the rise and threat of variants, and accelerating a return to normality," WHO said in a statement in May.

Biden and the other G-7 leaders are in the U.K. for the first meeting in about two years. The meeting is set to open Friday at Carbis Bay, a seaside resort in Cornwall in southwest England.

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