Health experts do not recommend unanimous testing of antibodies for COVID certificate – Bulgaria
Expert councils at the Ministry of Health do not unanimously recommend that antibody tests be the basis for issuing a certificate for COVID-19, but if the agency still decides to include the tests in the certificates in Bulgaria, it should be done every three months with one and same test. This is understood from the opinions of experts on virology,, Clinical Laboratory and clinical immunology, published on Monday night (November 8) on the website of the Ministry of Health.
Their positions are important because at the end of the last week the Deputy Ministers of Health Alexander Zlatanov and Toma Tomov announced that on the basis of the experts they will decide whether antibody tests will be valid in Bulgaria as a condition for issuing a COVID certificate. 19, which is valid in the country.
The letters answer four questions, chosen by the Minister of Health Stoycho Katsarov: what are the methods for determining antibodies, at what levels a person is protected from disease, what are the reference limits of research, how often should the tests be done.
How to determine antibodies
Prof. Iva Hristova, Director of the National Center for Infectious and Parasitic Diseases and Chief Coordinator of the Expert Council on Virology Summaries, the European Commission approved 595 antibody tests. “With this abundance of tests, comparing and unifying their results is extremely difficult due to the lack of standardization of tests at the moment,” sums up Prof. Hristova.
She and Assoc. Prof. Milena Velizarova, Chief Coordinator of the Expert Council for Clinical Laboratory, concluded that it was most appropriate to viral neutralizing antibody studies.
What are the levels of protection
All three expert councils write that there is a lack of scientific data on what levels of antibodies are needed to declare that the body is protected.
“The protective titer in the quantitative tests has not been specified,” wrote Prof. Mariana Murdzheva, chief coordinator of the expert council on clinical immunology. “The main problem is that measuring the concentration of antibodies is a quantitative indicator and the inappropriate properties of antibodies,” adds Prof. Murdzheva.
Assoc. Prof. Velizarova admits that since there is no standard for how many virus-neutralizing antibodies protect against disease, test manufacturers set their limits, which makes them “incomparable to each other.” Therefore, in order for all conclusions to be drawn again, “in order to monitor the concentration of virus-neutralized antibodies over time, the same method must be used, of one manufacturer of a diagnostic kit”, Associate Professor.
How often to do research
Prof. Hristova and Prof. Murdzheva pointed out that the tests for antibodies should be done every three months, while Assoc. Prof. Velizarova noted that “there is no scientific data” on how long the tests should be created so that they serve as evidence for protection against coronavirus.
“FDA (US Food and Drug Administration) defines the impossibility to predict how long the antibodies will be detected in patients of individuals, and that it is unknown at the moment whether they prove protective immunity “, writes Assoc. Prof. Velizarova. She explicitly states that the detection of antibodies is evidence of disease, but not is indicative of the degree of protection.
Prof. Hristova notes that when the quarterly tests reveal a lack of antibodies, a person should be vaccinated.