The head of the World Health Organization said on Monday that the planet can end the Covid-19 emergency this year, although the virus last week killed someone every 12 seconds.

"We can end Covid-19 as a global health emergency and we can do it this year," Tedros Adhanom Ghebreyesus told the UN health agency's executive board.

To do so, countries need to work harder to ensure equitable access to vaccines and treatment, track the virus and its emerging variants, and keep restrictions in place, he warned.

The WHO has for months demanded that countries do more to accelerate the distribution of vaccines in poorer nations, calling on all countries to vaccinate at least 70 percent of their populations by the middle of this year.

Half of the WHO's 194 member states missed the previous target of vaccinating 40 percent of their people by end-2021 and 85 percent of people in Africa were yet to receive a single jab, Tedros said.

"We simply cannot end the emergency phase of the pandemic unless we bridge this gap," he said.

"On average last week, 100 cases were reported every three seconds, and somebody lost their life to Covid-19 every 12 seconds," he added.

Covid-19 has killed more than 5.5 million people since it first emerged in late 2019 and case numbers have been driven to record levels by the new Omicron variant.

Since the strain was first detected in southern Africa nine weeks ago, Tedros said 80 million cases had been reported to the WHO -- more than in all of 2020.

Omicron appears to cause less severe disease than previous variants and Tedros confirmed that "the explosion in cases has not been matched by a surge in deaths".

The WHO chief said the world would need to learn to live with Covid.

"We will need to learn to manage it through a sustained and integrated strategy for acute respiratory diseases," he said, emphasizing it was "dangerous to assume that Omicron will be the last variant, or that this is the end game."

"On the contrary," he said, "globally the conditions are ideal for more variants to emerge."

"The potential for a more transmissible, more deadly variant remains very real."