The WHO said only 2-3% of people tested have COVID-19 antibodies, suggesting that 'immunity passports' may not be an effective policy

• The WHO's director general said data suggests no more than 2% to 3% of the population have the antibodies to show they were infected by the coroanvirus.
• These antibodies are needed to have immunity to the coronavirus before a vaccine is developed.
• A second WHO expert said the figure is less than expected, and undermines plans to create "immunity passports" as a route back to normal life.
• The WHO has also warned there's no evidence the coronavirus antibodies offer long-term immunity and that not all people who recover have the antibodies.
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The head of the World Health Organization warned Monday that likely no more than 2% to 3% of the global population have developed antibodies for COVID-19.

The suggestion is a problem for countries hoping to issue "immunity passports" as a way to get back to normal, even before a coronavirus vaccine has been developed.

A second WHO expert warned the data does not yet support such a strategy, not least because it is not clear whether those who recover from COVID-19 are in fact immune.

Dr Tedros Adhanom Ghebreyesus, the WHO director general, gave the 2% to 3% ballpark at a press conference on Monday, citing studies from around the world which the WHO has supported. He did not give details.

Dr Maria Van Kerkhove, the WHO's technical lead on COVID-19, said that the figure was lower than expected, according to the Guardian.

She also cast doubt on countries where officials are exploring ideas of offering "immunity passports" to those who are carrying antibodies. These countires include the US, UK, Germany, and Italy.

Chile has already endorsed the idea, and will this week issue them to some recovered people.

Of that idea, Van Kerkhove said: "Right now, we have no evidence that the use of a serological test can show that an individual has immunity or is protected from reinfection." Serological tests are those which test the blood for antibodies.

The presence of antibodies typicall makes a person immune to re-infection for at least a while. However, it is not yet clear what kind of protection is afforded by COVID-19 antibodies.

Some are optimistic. Dr. Anthony Fauci, the top US infectious disease expert, has previously said he is "willing to bet anything that people who recover are really protected against reinfection."

Some experts also hope antibodies from recovered patients could help treat other people with COVID-19.

Tedros, the director general, did not dismiss antibody tests entirely, but said they should be part of a broader response to the pandemic, alongside the more widespread tests to see whether a person is actively infected.

He said the WHO still welcomes the roll-out of antibody tests, which he said will help scientists "understand the extent of infection in the population."