BORIS Johnson is to urge world leaders to unite in the fight against disease as he hosts a global vaccine summit seeking to raise £6 billion to immunise 300 million children within five years.

The Prime Minister will on Thursday open the Gavi vaccine alliance meeting after insisting this was the “moment for humanity to unite” in the fight against coronavirus.

At Wednesday’s daily Downing St press conference, he said: “We need effective international action to reduce the impact of the virus across the globe…

“Health experts are agreed that if coronavirus is left to spread in developing countries, that could lead to future waves of infection coming back and reaching the UK.

“While our amazing NHS has been there for everyone in the country who needs it, many developing countries have health care systems that are ill-prepared to manage this pandemic. So, to ensure the world’s poorest countries have the support they need to slow the spread of the virus, tomorrow I will open the global vaccine summit hosted by the UK.”

The event will bring together more than 50 countries and leading figures like Microsoft founder Bill Gates to raise at least £6bn for the Gavi vaccine alliance.

During the next five years with the UK’s support as the alliance’s biggest donor – it has pledged more than £1.6bn over the period – the programme aims to immunise a further 300m children in the poorest countries against deadly diseases like typhoid, polio and measles to save millions of lives.

Mr Johnson said: “This support for routine immunisations will shore up poorer countries’ health systems to deal with coronavirus and so help to stop the global spread and prevent a second wave of the virus reaching the UK.

“This virus has shown how connected we are; we’re fighting an invisible enemy and no one is safe frankly until we are all safe and again this is all contingent upon each of us continuing to do our bit,” he added.