The World Health Organisation (WHO) said there were 21 million new coronavirus cases reported globally last week, the highest weekly number of Covid-19 cases recorded since the pandemic began.

But the number of deaths was largely unchanged, at more than 50,000, it added.

In its weekly assessment of the pandemic, issued late on Tuesday, the UN health agency said the number of new coronavirus infections rose by 5% and that the rate of increase appeared to be slowing. Half of regions reported an increase in Covid-19.

Earlier this month, the previous highest number of cases – 9.5 million – was recorded amid a 71% spike from the week before, as the hugely contagious Omicron variant swept the world.

WHO said the biggest increase in cases was seen in the Middle East, with a 39% rise, followed by a 36% jump in Southeast Asia. Deaths increased in Southeast Asia, the Middle East and the Americas, but fell in other regions.

WHO’s director-general Tedros Adhanom Ghebreyesus cautioned on Monday against talk that the pandemic might be entering its “endgame”, warning that conditions remained ripe for new variants to emerge, with vast swathes of unvaccinated people in some countries amid rapid virus transmission.

Dr Tedros said it might be possible for the world to exit the acute phase of the pandemic, if goals like immunising at least 70% of each country’s population were met later this year.

In Britain, researchers at Imperial College London recorded the highest-ever prevalence rate of Covid-19 in England earlier this month, estimating that about one in every 23 people tested had the virus.

The scientists said there were indications the massive spike caused by Omicron had started to level off but that infection rates remained high.

Scientists have said that Omicron is far less likely to cause serious disease and hospitalisation but spreads much faster than previous Covid-19 variants, including Delta.