Video report by political correspondent Libby Wiener
Prior to the meeting the prime minister pledged to donate the majority of the UK’s surplus vaccines to poorer nations.
Addressing the leaders from Downing Street, including US president Joe Biden in his first major multilateral meeting, Mr Johnson encouraged other developed nations to join the effort to increase the global vaccine supply.
He said: “Science is finally getting the upper hand on Covid which is a great, great thing and long overdue.
“But there is no point in us vaccinating our individual populations – we’ve got to make sure the whole world is vaccinated because this is a global pandemic and it’s no use one country being far ahead of another, we’ve got to move together.
“So one of the things that I know that colleagues will be wanting to do is to ensure that we distribute vaccines at cost around the world – make sure everybody gets the vaccines that they need so that the whole world can come through this pandemic together.”
There has been some criticism by the United Nations and World Health Organization (WHO) directed at rich nations after they secured the lions' share of all of the most promising vaccines, with many poor countries struggling to sign deals.
The prime minister used Friday’s online gathering to argue for an increase in funding for Covax, the multilateral global vaccine supply scheme being led by the WHO and other international bodies.
The push appeared to be well received, with the leaders issuing a joint statement afterwards agreeing to “intensify co-operation” on responding to the pandemic.
They committed to accelerating global vaccine development and deployment, including improving the sharing of information about the discovery of new variants, and cited £5.3 billion of support coming from the G7 for the body behind Covax.
Oxfam welcomed the steps taken by the G7 but said they still remain “insufficient when compared to the scale of the Covid-19 threat”.
In total, the UK has more than 400 million doses of vaccines on order – enough to vaccinate its population three times over.
But with some vaccines ordered yet to be approved by the UK medicines regulator and the domestic inoculation programme still in full flow, the government has not yet put a date on when the first Covax donations will be made.
When pressed on when the UK may be in a position to share extra vaccines with poorer countries, Foreign Office minister James Cleverly told the BBC: “There are a number of variables, some of which are in our control.
“We’re not really able to give with certainty either a timescale or the numbers involved.”
During the opening exchanges of the G7 meeting, Mr Biden could be seen laughing on the video call on the screen inside the Cabinet Room after the prime minister jovially accused the president’s campaign team of stealing the UK government’s “build back better” slogan.
“I think he may have nicked it from us but I certainly nicked it from somewhere else – probably some UN disaster relief programme,” Mr Johnson said.
With the UK acting as president of the G7 in 2021, Mr Johnson turned his attention to another of his priorities over the next year – climate change.
He told the leaders of the US, Japan, Canada, Germany, France and Italy: “I think that this is the right moment for us all to focus on the other great natural challenge about which we’ve been warned time and time and time again.
“We can’t ignore it, the warnings have been even clearer than they were for Covid, and that is the problem of climate change, and that’s why we’re going to be working very hard to get some great things done at G7 on our plans for the Cop26 summit that we are holding along with our Italian friends in Glasgow in November.
“It’s great, by the way, that Joe (Biden) has brought the United States back into the Paris climate change accords, a great step forward.”
As with many virtual meetings, the start of the call had some hitches.
German chancellor Angela Merkel appeared to forget to put herself on mute and inadvertently interrupted Mr Johnson’s opening remarks.
In video footage, Mr Johnson can be heard telling Ms Merkel she needed to press “mute”.
Friday’s online conference was the first meeting of G7 leaders since April 2020 and comes ahead of a summit in Cornwall in June, which Mr Johnson said he hoped could go ahead “face to face”.
Expressing his support for the G7 format, the Conservative Party leader added: “The G7 is the great gathering of like-minded, liberal, free-trading democracies.
“It is a very, very important forum.”