As cases of coronavirus infections fall and countries move to lift restrictions on movements, the debate should be about how to reopen safely rather than having to choose between lives and livelihoods, said a World Health Organisation (WHO) official.

Pitting public health against economic health is a false dichotomy, said WHO's regional director for the Western Pacific Takeshi Kasai, and countries instead need to think about how to manage both as they figure out a new way forward.

Speaking at the first World Economic Forum and WHO joint briefing on Covid-19, he warned that as long as there is no vaccine, and the coronavirus is circulating in any part of the world, everyone is at risk.

His remarks came as other WHO officials also warned against attempts to predict when the Covid-19 pandemic might end.

At a separate online briefing, WHO emergencies expert Mike Ryan described a vaccine as a "massive moonshot" while raising the possibility that the virus was here to stay.

"It is important to put this on the table: This virus may become just another endemic virus in our communities, and this virus may never go away," he said. "I think it is important we are realistic and I don't think anyone can predict when this disease will disappear."