The World Health Organization has warned that there is currently no evidence that people who have recovered from COVID-19 and have antibodies are protected from reinfection.
The information is framed in the form of a scientific note and published in connection with the discussed proposal of the governments of several countries to introduce the so-called “passports of immunity”, which would allow ill people to travel freely or return to work.
Some governments, wanting a gradual return to work and the resumption of economic activity, put forward the idea of creating a document confirming, on the basis of serological tests, detecting the presence of antibodies in the blood of people and their immunity to the new coronavirus.
But the effectiveness of protection against SARS-CoV-2 thanks to antibodies has not yet been established by any scientific research.
“There is currently no evidence that people who have recovered from COVID-19 and have antibodies are protected from reinfection”, – the WHO statement said.
“As of April 24, 2020, no studies have evaluated whether antibodies are present to SARS-CoV-2 immunity to subsequent infection with this virus”.
It is also noted that not all patients develop a sufficiently strong immune response, and some of those who have “have a very low level of neutralizing antibodies in the blood”.
WHO believes that at this stage of the pandemic, in order to guarantee people that there is no risk of re-infection, there is insufficient data on how strong the antibodies provide immunity.
Moreover, according to WHO, the use of such “passports” or certificates may create the illusion of security among their owners, they will no longer comply with public health recommendations, which will further increase the risk of spreading the disease.
Another factor that, according to an international organization, makes it premature to discuss the introduction of such documents, is the unreliability of the tests themselves.
“Currently used serological tests need additional verification to determine their accuracy and reliability”, – the document says.
“Firstly, they may mistakenly mark people who have been infected as negative, and secondly, people who haven’t were infected, falsely flagged as positive. Both errors have serious consequences and will affect efforts to control the spread of the disease”.
Experts also note that these tests do not distinguish the immune response to a new coronavirus from antibodies of other known human coronaviruses, four of which are widespread in the population and cause mild colds. Two more are responsible for SARS – Severe Acute Respiratory Syndrome, and MERS – Middle Eastern Respiratory Syndrome.
“People infected with one of these coronaviruses are capable of producing antibodies that interact with antibodies produced in response to SARS-CoV-2 infection”, – the WHO report says.