The World Health Organization (WHO) said on Saturday that there was currently ‘no evidence’ that people who have recovered from COVID-19 and have antibodies are protected from a second coronavirus infection.
In a statement, the United Nations agency warned against issuing ‘immunity passports’ or ‘risk-free certificates’ to people who have been infected, saying the practice may actually increase the risk of spread as they may ignore standard advice.
The UK has carried out fewer than 5,000 antibody tests so far – despite mass schemes being carried out across the globe.
A healthcare worker performs a coronavirus antibody test at a SOMOS Community Care COVID-19 antibody walk-in testing site, Brooklyn, New York City, U.S., April 24, 2020
Until now the antibody tests had been considered the key to letting countries out of lockdown, allowing officials to get a clearer picture of the true size of the coronavirus outbreak.
Chile said last week it would begin handing out ‘health passports’ to people deemed to have recovered from the illness. Once screened to determine if they have developed antibodies to make them immune to the virus, they could immediately rejoin the workforce.
Italy has screened the blood of 20,000 people a day using the test, while one programme in the US planned to screen 40,000 healthcare workers.
Germany had begun to test 15,000 people, with plans to apply the findings to its whole population, and even Andorra has ordered 150,000 kits – enough to give its entire population two each.
Antibodies are proteins in the blood which reveal if someone has already fought off an infection, including the deadly coronavirus.
A medical personnel shows a rapid antibody test kit for COVID-19, at a school converted into a mass testing facility on April 24, 2020 in Manila, Philippines
A statement from the World Health Organisation explained that while most people appear to have produced antibodies to the Covid-19 virus in their recovery, it is not known if the presence of these antibodies in the blood is enough to stop a second infection.
The World Health Organisation said: ‘WHO continues to review the evidence on antibody responses to SARS-CoV-2 infection. Most of these studies show that people who have recovered from infection have antibodies to the virus.
‘However, some of these people have very low levels of neutralizing antibodies in their blood, suggesting that cellular immunity may also be critical for recovery.
‘As of 24 April 2020, no study has evaluated whether the presence of antibodies to SARS-CoV-2 confers immunity to subsequent infection by this virus in humans.’
The organisation also notes that the antibody tests may ‘falsely catagorize people in two ways’, labelling people who have been infected as negative and those who have not as positive – leading to potentially deadly results.
People have lunch outdoors at a restaurant in Stockholm, Sweden, on Wednesday, in a country which has not imposed a draconian lockdown
This graph compares the infection rates in the UK and Sweden, with the world figure shown for comparison. The UK’s rate has been consistently worse than Sweden’s since March 28, five days after Boris Johnson announced a lockdown
Adding: ‘At this point in the pandemic, there is not enough evidence about the effectiveness of antibody-mediated immunity to guarantee the accuracy of an ‘immunity passport’ or ‘risk-free certificate.’
‘People who assume that they are immune to a second infection because they have received a positive test result may ignore public health advice.
‘The use of such certificates may therefore increase the risks of continued transmission. As new evidence becomes available, WHO will update this scientific brief.’
The news comes as Former Chancellor Philip Hammond today urged Britons to face the ‘reality’ that the UK must get back to work while people are still suffering with Covid-19.
Former chancellor Philip Hammond who has called on ministers to set out plans to begin easing the coronavirus lockdown and re-start the economy
He told the Government to publish an exit plan outlining a strategy to ease the coronavirus lockdown and restart the economy.
Mr Hammond said the country could not afford to wait until a vaccine had become available before resuming more normal economic activity.
Sweden, who has now enforced lockdown after initially relying on herd immunity, has seen a recent surge in cases and deaths due to the virus.
Sweden posted a record 812 new Covid-19 cases yesterday, adding 61 to the record 751 tally it reached the day before – with an additional 131 new deaths, leaping from 84 on Thursday.
Sweden’s top disease expert Anders Tegnell (pictured in Stockholm last week) said that a full-scale lockdown may not have prevented care home deaths
Speaking to BBC Radio 4 state epidemiologist Anders Tegnell said Sweden might withstand a ‘second wave’ better than other countries because its light-touch measures could be kept in place for longer than the draconian lockdowns elsewhere.
Sweden’s cases have been rising more slowly than Britain’s, but it has far more infections and deaths than the rest of Scandinavia.
Asked whether a lockdown would have prevented those deaths, Tegnell said it was a ‘very difficult question to answer at this stage’.
‘At least 50 per cent of our death toll is within elderly homes and we have a hard time to understand how a lockdown would stop the introduction of disease’, he said.
‘We already had a law making it illegal for visitors to come to elderly homes. They need constant care, they need a lot of people coming and going to take care of them.
‘So it’s a bit unclear to us if a lockdown really would have stopped this from happening or not.
‘It’s a difficult question and I don’t think we have the answer and I’m not sure we’ll ever get the answer completely.’
Saying that Sweden had passed the peak of the epidemic a week ago, Tegnell said as many as 20 per cent of Stockholm residents may already have had the virus.
‘We believe that we have an immunity level, if I remember rightly, somewhere between 15-20 per cent of the population in Stockholm,’ he said.
‘[This is] not complete herd immunity but it will definitely affect the reproduction rate and slow down the spread.’