“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,” WHO emergencies expert Mike Ryan told an online briefing on Wednesday.

“I think it is important we are realistic and I don’t think anyone can predict when this disease will disappear,” he added.

“I think there are no promises in this and there are no dates. This disease may settle into a long problem, or it may not be.”

However, he said the world had some control over how it coped with the disease, although this would take a “massive effort” even if a vaccine was found – a prospect he described as a “massive moonshot”.

More than 100 potential vaccines are being developed, including several in clinical trials, but experts have underscored the difficulties of finding vaccines that are effective against coronaviruses.

Ryan noted that vaccines exist for other illnesses, such as measles, that have not been eliminated.

Spain virus study

It comes as a study shows that up to 5.0 per cent of Spain’s population – 2.3 million people – could be infected with the coronavirus.

The antibody study included about 90,000 people in 36,000 households and was designed to give an idea of the true extent of the viral outbreak in Spain.

That would far surpass the official count of 229,000 known infections.

However, health authorities have long known that the number must be too low, since most tests have been on people displaying symptoms or on people working in health care.

Many people get the virus and never display any symptoms. But many come down with the potentially fatal respiratory disease COVID-19.

Designed to provide more concrete data about the virus’ spread, participants were given two different tests three times three weeks apart.

Results showed that the population of hard-hit Madrid had an infection rate of about 10 per cent, while the Canary Islands or Mallorca only had rates of about 2.0 per cent.

But experts caution that the tests sometimes yield false positives if a person has been exposed to any other kind of coronavirus.

Pandemic’s economic hit

The world economy could shrink by 3.2 per cent this year amid the coronavirus pandemic, the United Nations says.

In the worst-case scenario, it could even contract by 4.9 per cent, according to the UN World Economic Situation and Prospects mid-year report.

Before the coronavirus outbreak, the UN expected world output to expand at a pace of 2.5 per cent in 2020.

Global economic output is expected to be slashed by nearly $US8.5 trillion ($A13.1 trillion) this year and next, wiping out much of the gains of the past four years, according to the new report.

Gross domestic product growth in developed economies is expected to plunge by up to 5 per cent this year, marking the sharpest contraction since the Great Depression in 1930s.

The report warned that there is a strong possibility of a slow recovery and prolonged economic slump, with rising poverty and inequality.

The crisis will push an estimated 34.3 million people below the extreme poverty line this year, the UN said.

Next year could result in modest 3.4-per-cent growth, the report said.

-with AAP

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