The Group of Seven nations will commit at least 1 billion Covid-19 shots to poorer countries through sharing and financing programs during its summit Friday and help vaccinate the world by the end of next year.

The UK, which is hosting the G-7 gathering in England, said it would donate at least 100 million doses within 2022, including 5 million in the coming weeks, British Prime Minister Boris Johnson said, according to Agence France-Presse.

U.S. President Joe Biden pledged to donate 500 million doses and made a preliminary survey of a joint effort by advanced economies to make immunization widely and readily available everywhere.

"At the G-7 summit I hope my fellow leaders will make similar commitments so that, together, we can vaccinate the world by the end of next year," The Associated Press quoted Johnson as saying in a statement. The G-7 includes Canada, France, Germany, Italy and Japan.

But some campaign advocates were dismayed and called it a drop in the ocean. Oxfam projects around 4 billion people will depend on COVAX for vaccines, the program that distributes shots to low and middle income nations, according to Reuters.

With the world's population nearing 8 billion, and most people needing two doses, campaign groups said the pledges were a start but world leaders needed to go much further and faster.

"The G-7's objective to provide 1 billion doses should be viewed as an absolute minimum, and the timeframe needs to speed up," Lis Wallace, director of UK Advocacy at The ONE Campaign, said.

COVAX has distributed 80 million doses worldwide - and some parts of the world, particularly Africa, remain "vaccine deserts," The Associated Press said.

Nearly 4 million people have died from the virus. The international economy has been wrecked. Infections have been reported in more than 210 countries since the first cases were detected in China in December 2019.