Dr Tedros Adhanom Ghebreyesus, Director-General of the World Health Organization
The World Health Organization (WHO) warned on Saturday that recovering from coronavirus may not protect people from reinfection as the death toll from the pandemic approached 200,000 around the globe but has since updated this statement after an outpouring of confused queries from the public.
It earlier questioned if so-called “immunity passports” or a “risk-free certificate” would be reliable given current testing capabilities. However, it has since issued a statement saying most people will likely develop an anti-body response.
“There is currently no evidence that people who have recovered from Covid-19 and have antibodies are protected from a second infection,” the WHO said in the original statement.
What we don't yet know is the level of protection or how long it will last. We are working with scientists around the world to better understand the body's response to #COVID19 infection. So far, no studies have answered these important questions. pic.twitter.com/DisLjWCa4U
— World Health Organization (WHO) (@WHO) April 25, 2020
From the medical research carried out so far, studies indicate that individuals who had recovered from infection did carry antibodies in their blood – but some of them showed only very low levels of antibodies. This pointed to the significance of another part of the body’s immune response playing its part. These are called T-cells and work to eliminate infected cells which are critical for the recovery of infected individuals.
To date, no study has evaluated whether the presence of antibodies to the virus presented immunity to subsequent infection, the WHO said.
“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,” it said.
The organization also caveated that any research into antibody effectiveness will need further validation to determine their accuracy and also needed to distinguish between the previous infection by the SARS-CoV-2 virus – which has caused the pandemic – and the six other known strains of coronavirus in circulation.
The organization updated its position on this in a tweet that was posted in a bid to clarify some confusion around this statement:
Earlier today we tweeted about a new WHO scientific brief on "immunity passports". The thread caused some concern & we would like to clarify:
We expect that most people who are infected with #COVID19 will develop an antibody response that will provide some level of protection. pic.twitter.com/AmxvQQLTjM
— World Health Organization (WHO) (@WHO) April 25, 2020
Last week Professor Mala Maini from University College London said reliable antibody tests were urgently required if we are to determine how long antibodies persisted and how effective they are against re-infection.
“We’re not yet sure if these antibodies indicate protective immunity against SARS-CoV-2 but preliminary data suggest they may be a reasonable proxy for this – so they are being considered to inform release from lockdown, etc,” she said.
Meanwhile, the UAE has conducted more than one million tests for coronavirus, the government announced on Saturday night. The Ministry of Health and Prevention also confirmed a further 532 new Covid-19 cases, taking the country’s total to 9,813 cases with seven deaths and 127 recoveries.
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