At the end of the G7 summit in Cornwall, the PM said countries were rejecting "nationalistic approaches".
He said vaccinating the world would show the benefits of the G7's democratic values.
There was also a pledge to wipe out their contribution to climate change.
After the first meeting of world leaders in two years, Mr Johnson said "the world was looking to us to reject some of the selfish, nationalistic approaches that marred the initial global response to the pandemic and to channel all our diplomatic, economic and scientific might to defeating Covid for good".
He said the G7 leaders had pledged to supply the vaccines to poor countries either directly or through the World Health Organization's Covax scheme - including 100 million from the UK.
The communique issued by the summit pledges to "end the pandemic and prepare for the future by driving an intensified international effort, starting immediately, to vaccinate the world by getting as many safe vaccines to as many people as possible as fast as possible".
It also includes steps to tackle climate change, with leaders re-committing to the target of reaching net zero greenhouse gas emissions by 2050 at the latest and pledging to eliminate most coal power.
Mr Johnson rejected suggestions the vaccines pledge was a moral failure by the G7 as it was not enough to cover the needs of poorer countries.
He referred to the the UK's involvement in the development of the Oxford-AstraZeneca vaccine.
"Already of the 1.5 billion vaccines that have been distributed around the world, I think that people in this country should be very proud that half a billion of them are as a result of the actions taken by the UK government in doing that deal with the Oxford scientists and AstraZeneca to distribute it at cost," he said.
He added that "we are going flat out and we are producing vaccines as fast as we can, and distributing them as fast as we can".
The target to vaccinate the world by the end of next year would be met "very largely thanks to the efforts of the countries who have come here today", Mr Johnson said.