Boris Johnson has rejected suggestions that there may be an “unforgivable moral failure” in the supply of vaccine doses to cover the needs of poor nations – saying half a billion doses of the Oxford jab have already been sent around the world.

Leaders of the major industrialised nations at the G7 summit in Cornwall pledged more than 1 billion doses of Covid-19 vaccine – either directly or through funding to the Covax initiative – to poor countries.

The Prime Minister said this was made up of “a massive contribution by the United States and other friends”, but one of his predecessors, Labour’s Gordon Brown, said the G7 summit “will go down as a missed opportunity” due to the lack of a plan to deliver 11 billion vaccine doses.

Mr Johnson told a news conference at the end of the G7 summit yesterday that “we are going flat out and we are producing vaccines as fast as we can, and distributing them as fast as we can.

“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.”

The Oxford jab was developed by scientists working at the Churchill Hospital site in Headington.

The target to vaccinate the world by the end of next year will be done “very largely thanks to the efforts of the countries who have come here today”, Mr Johnson said.

He said the UK’s contribution to the 1 billion dose pledge is another 100 million vaccines from now to next June.

Earlier Mr Brown said the summit could be seen as an “unforgivable moral failure” due to the gap in vaccinations between rich and poor nations.

He told Sky’s Trevor Phillips On Sunday programme: “When we needed 11 billion vaccines, we’ve only got offered a plan for 1 billion.”

He added: “I think this summit will also go down as an unforgivable moral failure, when the richest countries are sitting around the table with the power to do something about it.

“Now that we’ve discovered the vaccine, we have not delivered the comprehensive plan that will deliver vaccination by the middle of next year. We will have a huge problem of a division between the richest countries that are safe and the poorest countries that are not safe.

“But then the problem will come back to haunt the richest countries because we will have contagion spreading that will hurt even the people who are vaccinated because of mutations and variants.”

Read more: Today's coronavirus figures for the county

Mr Johnson said that no final decision had been taken on lifting coronavirus restrictions on June 21. The decision is expected today.