Just hours after U.S. President Joe Biden pledged to donate of 500 million Pfizer shots, British Prime Minister Boris Johnson said Britain would grant at least 100 million surplus vaccines to the poorest nations.

Johnson expects the Group of Seven (G7) to agree to donate 1 billion COVID-19 vaccine shots to poorer countries during its summit starting on Friday, and help vaccinate the world by the end of 2022.

Some campaign groups condemned the plan as a drop in the ocean, with Oxfam estimating that nearly 4 billion people will depend on COVAX for vaccines, the program that distributes COVID-19 shots to low and middle income countries.

“In doing so we will take a massive step towards beating this pandemic for good.”

COVID-19 has killed around 3.9 million people and ripped through the global economy, with infections reported in more than 210 countries and territories since the first cases were identified in China in December 2019.

While scientists have brought vaccines to market at breakneck speeds – Britain has given a first dose to 77 percent of its adult population and the United States 64 percent – they say the pandemic will only end once all countries have been vaccinated.