The World Health Organisation (WHO) has launched a plan to vaccinate the world, motivated by fears that a new jab-resistant coronavirus variant could emerge “very soon”.

United Nations leader Antonio Guterres told a WHO press conference that the UK and other developed nations were being “stupid” by not concentrating supplies in places such as Africa, risking the emergence of variants that could undo global efforts in fighting the pandemic so far.

The WHO’s plan, called the Strategy to Achieve Global Covid-19 Vaccination, has set targets of immunising 40% of the population of every country by the end of 2021, and 70% by the middle of 2022.

The strategy requires at least 11 billion vaccine doses, which can be fulfilled by the current global monthly supply rate of almost 1.5 billion doses, the organisation has said.

It involves vaccinating all older adults, health workers and high-risk groups first, followed by all other adults, and finally adolescents.

Speaking at the WHO press conference on Thursday, Mr Guterres said: “If we let the virus spread like wildfire in the global south, we know that variants will emerge, and we know that there is a risk that one day, and that day can be very soon, there will be another variant that will be able to resist vaccines.

“And all the vaccination effort made in developed countries will fall apart, and these people will not be protected.

“So not to have equitable distribution of vaccines is not only a question of being immoral, it is also a question of being stupid.”

Mr Guterres said the WHO’s strategy should be implemented by a task force comprising vaccine production countries, Covax, international financial institutions and pharmaceutical companies.

WHO’s director-general, Dr Tedros Adhanom Ghebreyesus, said 56 countries did not reach the 10% vaccination rate set as a target by the WHO for the end of September this year.

Dr Ghebreyesus said: “Vaccine equity will accelerate the end of the pandemic.

“Achieving the WHO’s vaccine equity targets will substantially increase population immunity globally, protect health systems, enable economies to fully restart, and reduce the risk of new variants emerging.”

He added though that the WHO has “no power” to force higher-income countries to share their supplies more with lower-income nations.

On the subject of booster jabs, Dr Bruce Aylward, senior adviser to the director-general at the WHO, said: “Every single dose makes a difference, we need to make sure every dose right now is going into people who haven’t received any doses, not additional doses going into those who already have.”

The WHO previously called for a moratorium on booster doses until the end of 2021 so vaccines could be shipped to parts of the world where many at-risk people remain unvaccinated.

It said that while third doses may be necessary for immunocompromised people, widespread booster jabs could be put to better use elsewhere.