Detection of antibodies and immune response against Covid-19 virus infection by high sensitivity immunoassay method (Centaur XPT) from venous blood.
Based on the new serological test, we are able to determine whether there are antibodies present in people has undergone COVID-19 infections, that provide protection against the disease. Venous blood from patients shows that they have an antibody (total immunoglobulin) that neutralizes the part of the SARS-CoV2 virus’s S-spike protein that is responsible for getting the virus into the cell.
This test can not only determine if someone has gone through the infection, but can also detect the level of protection developed, which correlates with the presence and amount of neutralizing antibodies.
This serological method is so much more informative than ELISA or other immunochemical methods that detect only “S” protein, that our test shows the level of antibodies that bind to a specific part of the S protein called the receptor binding domain (RBD). Antibodies that interact with RBD prevent the virus from binding to the ACE receptor, thus preventing the virus from entering the cell.
Why is it beneficial to do the test?
The Centaur test quantifies the level / status of an antibody that provides antibody protection to an individual. The measured value is proportional to the amount of neutralizing antibodies circulating in the blood, which also provides information on the effectiveness (timing) or need for vaccinations.
Test sensitivity
The assay detects IgG positivity with 99% sensitivity and 100% specificity. Rarely, cross-reactions may occur due to past or current infection with other coronaviruses such as SARS-CoV-1, MERS-CoV, HKU1, 229E, NL63 or OC43, or antibodies already present.
When and who should be tested?
It is recommended for patients who have either been confirmed by PCR to have Covid-19 disease or who are suspected of being asymptomatic but may have become infected and who have had at least 14 days since the disease or suspected infection. The test should also be performed for those who have been found to be IgG positive by other laboratory methods and want to know exactly whether and in what amount the antibodies are present in their body. It is advisable to perform the serological test periodically after the first positive result.
How to interpret the test results?
Positive result
Immune response against SARS-CoV-2 can be detected in your body, which means antibody protection, but we do not know how long immunity to the disease lasts.
Negative result
A negative result means that your body does not have a detectable amount of antibodies against the SARS-CoV2 virus.
There could be several reasons for this:
- You’re not infected
- You are infected, but you are at an early stage of the infection when no antibody can been detected yet
- You are infected but your body does not have a detectable amount of neutralizing antibody to the SARS-CoV2 virus