World leaders must join together in the fight against disease, Boris Johnson has said, as he announced that almost £7 billion has been raised at a UK-hosted global vaccine summit.

The Prime Minister said up to eight million lives would be saved thanks to funds pledged at the Gavi vaccine alliance conference, held virtually, on Thursday.

Organisers set out to raise £6 billion to immunise 300 million children against infectious diseases like polio, diphtheria and measles within five years, but surpassed the target.

Mr Johnson urged foreign leaders to “fortify this lifesaving alliance”, telling them the “triumph of humanity over disease” is the “greatest shared endeavour of our lifetimes”.

He also used the conference, which comes against the backdrop of the coronavirus pandemic, to ask leaders to renew their “collective resolve” to find a Covid-19 vaccine.

The Prime Minister said the UK has already committed “up to £764 million for the global coronavirus response and I’m proud to say that some of the most promising research into vaccines is happening right here in the UK, supported by our vaccines taskforce”.

“We are pioneering innovative collaborations that will be needed to manufacture and distribute a vaccine once we’ve found it, like the partnership between AstraZeneca and the University of Oxford,” he said.

“Just as we have … great military alliances, like Nato, where countries collaborate on building their collective military defence … We now need the same spirit of collaboration and collective defence against the common enemy of disease.

“It will require a new international effort to co-operate on the surveillance and the sharing of information – data is king – that can underpin a global alert system, so we can rapidly identify any future outbreak. And it will mean a radical scaling up of our global capacity to respond.”

Speaking at a virtual meeting later on, cabinet minister Anne-Marie Trevelyan said she believes the UK is capable of delivering a coronavirus vaccine to anyone who needs it “at speed” when one becomes available.

The International Development Secretary said: “Those of us with strong healthcare systems like in the UK, we have systems, public health systems to deliver that vaccine when we get it, at speed across our country to care workers and to the most vulnerable and then to everyone else who needs it.”

Opening the conference earlier in the day, Mr Johnson said: “To defeat coronavirus, we must focus our collective ingenuity on the search for a vaccine and ensure that countries, pharmaceutical companies and international partners, like the World Health Organisation, co-operate on a scale beyond anything we have seen before.

“We must use the collective purchasing power of Gavi, the vaccine alliance, to make that future vaccine affordable and available to all who need it.

“If we are to make this the beginning of a new era of global health collaboration, we must also replenish the funding for the vaccines we already have, strengthening the routine immunisation against preventable diseases in the poorest countries.”

Microsoft founder Bill Gates donated 1.6 billion US dollars (£1.3 billion) from his foundation to “help Gavi continue its amazing work for the next five years”.

He said: “In addition, the foundation is proud to support the new Covid-19 vaccine advance market commitment, with a 100 million US dollar (£79,375,000) contribution to help make sure that when a Covid-19 vaccine is discovered, everyone who needs it can have access – starting with healthcare workers and other high-risk populations.”

And US president Donald Trump, in a video clip filmed outside the White House, said: “As the coronavirus has shown, there are no borders, it doesn’t discriminate, it’s mean, it’s nasty but we’re going to all take care of it together.”