COVID-19 Antibody Test Results in Labs Vary: Ministry Urged to Change Passport Procedures for Options

Currently, the Opportunity Passport can be obtained in a variety of ways, from the COVID-19 vaccination to COVID-19, to a negative PCR or rapid antigen test, or a positive antibody test. According to Vidas Gedutis, CEO of preventive-diagnostic health care services company Antėja Laboratorija, it is the use of antibody tests to obtain a passport that is controversial by doctors.

The lab approached Health Minister Arūnas Dulkis with a request to change the current procedure when both general antibody tests and IgG antibody tests are suitable for obtaining a passport, according to the press release.

In Lithuania, different quantitative tests for COVID-19 are carried out: general antibodies (IgM, IgA, IgG) and only IgG antibodies. According to Eglė Marciuškienė, laboratory medical consultant and laboratory physician, the IgG test against the protein “needle” (Anti-S) allows to determine more precisely if a person has an immune response to COVID-19 infection, when the general antibody test for COVID-19 is not available, such targets.

Different test methods can lead to different test results; for example, in a laboratory that detects IgG antibodies, the client may receive a negative test result when a test performed by another laboratory for a common antibody test may already be positive.

“Naturally, many people don’t understand the differences between specific tests and are surprised that they can get a passport for one lab test, but not another lab test. Due to the confusion, some customers unjustifiably complain about the quality and accuracy. of tests, and some just take advantage of the situation: they perform antibody tests in several laboratories, hoping that at least one test will be positive and they can get a passport, “said the laboratory director.

The role of antibody research has been distorted

V. Gedutis noted that after the Opportunity Passport came into effect, the role of antibody research changed. “The purpose of these tests is to detect antibodies after vaccination or to show that a person is infected with coronavirus. Unfortunately, we now have a situation where blood analysis laboratories become institutions that determine whether a person will receive a passport or not, ”commented the head of the laboratory about the current procedure.

It is important to understand that the passport of opportunity is issued on the assumption that the person is currently protected against infection and is also safe for others – they do not carry or spread the pathogen. Only by choosing the correct antibody test, the answer may be whether we can have at least partial protection against the COVID-19 virus.

E. Marciuškienė emphasized that antibodies have a certain period of life. Scientific studies provide evidence that peak antibodies are rapidly depleted in patients who have been diagnosed with mild COVID-19 symptoms and have recovered. The half-life of these antibodies was 36 days. This means that the 2-month opportunity passport expiration date when weak positive antibodies are obtained is inappropriate.

Peculiarities of different coronaviruses.

The doctor also pointed out that the tests do not differ only in the classes of antibodies detected. Antibodies produced against different viral proteins can be tested. The importance of these antibodies varies.
Some viral structures are common to all coronaviruses: 7 different coronaviruses (229E, NL63, OC43, HKU1, MERS-CoV, SARS-CoV, and the new SARS-CoV-2) are known to cause cold or respiratory tract symptoms higher. disease in humans. Therefore, if a person has ever had a coronavirus infection, antibodies can be found in their blood. The protein S (needle) of the COVID-19 infection virus is more variable and more specific. It also reflects the actual immune response of the body in case of SARS-CoV-2 or after vaccination, since all current vaccines are based in one way or another on the activity of the anti-S protein.

“Despite all the explanations described, there are still many questions that modern science still cannot answer. Sometimes it is even obtained that the data of scientific studies are completely contradictory. There is confusion about the variety of research reagents on the market and the lack of regulation of the situations in which they are suitable for use. Understanding the fully justified question of why the results of the tests carried out in different laboratories differ, we ask the responsible authorities to review the current procedure for conducting the tests, the selection of reagents and the issuance of the option passport and provide an explanation ” said E. Marciuškienė.