Coronavirus (SARS-Cov-2) Spike (S) Protein | Antibodies & Home Services

The SARS-Cov-2 Spike (S) Protein Neutralizing Antibody Test can be used to monitor antibody titers after vaccination and / or to assess immune status after Covid-19 infection.

This price is valid only in Batumi and Tbilisi.

General Information

Infection with the SARS-CoV-19 virus, which causes Covid-2 infection, develops a complex immune response, which involves the production of specific antibodies to viral antigens - the so-called "spike" (S) and nucleocapsid (N) proteins.

A humoral immune response study conducted on a group of 2 patients with virologically confirmed SARS-CoV-285 infection showed that within 19 days of the onset of symptoms, all patients had a positive test for IgG antibodies. Also, IgM or IgG seroconversion was performed simultaneously or sequentially, and after seroconversion, the antibody titer reached the plateau within 6 days. (In immunology, seroconversion is the production of specific antibodies in blood serum as a result of infection or immunization).

Interestingly, additional serological examination of 19 contacts of patients with Covid-164 infection identified a small group of people (4.3%) with negative PCR (PCR) results who detected virus-specific IgG or IgM antibodies, indicating that this test may Be useful for monitoring asymptomatic contacts of infection.

Another study (Sun et al.) Examined the kinetics of anti- (N) nucleocapsid and anti- (S) protein-specific IgM and IgG antibodies. 19 samples from 38 patients with Covid-130 were analyzed, which showed that seroconversion of N-IgM, N-IgG, S-IgM and S-IgG antibodies was gradual, within 1-3 weeks after the onset of symptoms.

N-IgM and S-IgM antibodies peaked in the second week, while N-IgG and S-IgG antibodies continued to grow in the third week. Total detection of N-IgM, N-IgG, S-IgM and S-IgG antibodies detects 75% of infections in the first week, 94,7% in the second week and 100% in the third week after the onset of symptoms.

As for the vaccines available from the end of 2020, they fully encode the "Spike" (S) protein. Consequently, the antibodies produced after vaccination have a strong neutralizing ability to target the so-called "spike" protein-binding domain, the so-called Against RBD.

Test advantages:

• This test determines the total number of antibodies (including IgG antibodies) that are produced in a patient's blood serum against the RBD (receptor-binding domain) site of the viral antigen - the "Spike" protein (S1 subunit).
• Method: Electrochemiluminescence (ECLIA), fully automatic closed system. Analyzer Cobas e 411; Manufacturer: Roche (Germany).
• High specificity (100%) and sensitivity (98.8%).
• Quantitative evaluation of the humoral immune response allows us to monitor the dynamics of patients' immune responses by determining the specific antibody titer. 

When should we take the test?

• Evaluation of the immune response after vaccination;
• Assessment of the immune response (SARS-CoV-2) after Covid-19 infection.

How to prepare for the test?

No special training is required

A venous blood sample is required for the test.

Follow the rules of epidemiological safety!

Possible interpretation of the results

• <0.8U / mL - Negative (negative).
• ≥ 0.80 U / mL - positive (positive).
• Positive result Indicates newly or previously transmitted SARS-CoV-2 infection and / or post-vaccination immune response.
• Negative result Indicates no contact with SARS-CoV-2 virus. Also, a negative result does not rule out the absence of SARS-CoV-2 infection if the test was performed before antibody production or after vaccination, as well as in patients with weakened immunity.