The representatives of the world health organization specify a briefing in Geneva on 17 April to the lack of evidence that the antibody tests can show the presence of immunity to coronavirus. Briefing video published on the YouTube channel of the organization.
Technical lead of the who programme on emergency health Maria van Kerkhove noted that many countries want to use serologic tests (antibody tests) to determine immunity to the coronavirus, but she cautioned against such a method.
“Now we have no evidence that serological test might show that a person is immune or protected from re-infection. These tests can measure the level of antibodies in the human body after a week or two after infection,” said van Kerkhove and stressed that “the presence of antibodies does not mean that someone is immune”.
Her colleague Michael Ryan, Executive Director of the who programme on emergency situations in the areas of health, pointed to the ethical side of the issue.
“There are serious ethical issues associated with the use of this approach, and we must be very careful to treat this. We need to study the degree of protection that can give antibodies. No one is sure whether the protected person with antibodies from re-infection. In addition, some tests have problems with sensitivity, they can give a false negative result. Someone who considers themselves to be seropositive and protected, in fact in some situations could be at risk,” said Ryan.
Who promised to soon issue updated guidance on this issue.
To identify the coronavirus SARS-CoV-2 in humans worldwide widely used testing by polymerase chain reaction (swabs taken from the mucosa of the nasopharynx and oropharynx). In a serological test analyzes blood serum, said publishing The Conversation. These tests are not looking for the virus itself and the antibodies that the immune system of the body produces to fight infection. Because antibodies do not appear immediately, serological tests are ineffective in the early stages of infection. One of the advantages of serological testing is the ability to determine the infection of people who have had asymptomatic, and therefore not taken into account in the overall statistics, said the publication of The Conversation.
Some countries have announced plans to conduct serological testing during the release from quarantine. For example, this was reported by the American Management on sanitary inspection behind quality of foodstuff and medicines. “The results of these tests can help to determine who was infected and developed antibodies, which can protect against future infection and to identify those who are still in danger,” – said in a statement from April 18. About plans to test for antibodies was announced by the Ministry of health of Ukraine.
An outbreak COVID-19 began in December 2019 in the Chinese city of Wuhan. March 11, 2020, the who announced the spread of the coronavirus pandemic. According to data from the American Johns Hopkins University, the number of confirmed cases of coronavirus in the world exceeded 2.4 million, more than 635 thousand people have recovered, and 166 thousand died.
This month South Korea announced re-infected people who recover COVID-19. In the country investigating the causes of the incident, but do not rule out problems with the tests.