Anti SARS CoV 2 (COVID-19) IgG antibodies to the spike (S) protein assay
Determination of class IgG antibodies to the S-protein of SARS-CoV-2 coronavirus (COVID-19) in serum by enzyme-linked immunosorbent assay (ELISA)
Required for the determination of antibodies to the S-protein of coronavirus, which is produced after vaccination, forming an immune response. It is necessary to do ELISA for IgG antibodies to S-protein on day 42 after the first dose of the vaccine, that is after 6 weeks. SARS-CoV-2 virus (severe acute respiratory syndrome coronavirus‑2) is an enveloped single-stranded RNA virus and is a member of the coronavirus family Coronaviridae.
Coronaviruses are composed of the following structural proteins: spike protein (S), envelope protein (E), membrane protein (M) and nucleocapsid (N) protein, and several non-structural proteins.
The immune system reacts to SARS-CoV-2 by producing specific antibodies. Antibodies in the blood serum of infected individuals are reportedly detected after the detection of the virus RNA in smears, several days (sometimes up to 2 weeks) after the first symptoms appear. Specific IgG antibodies to SARSCoV-2 can be detected in patients with COVID-19 during the symptomatic phase of the disease, when the RNA of the virus is no longer detected.
The sensitivity of the combined RNA and antibody test to SARS-CoV-2 is > 99%. As a rule, after a disease, antibodies are produced to both the nucleocapsid (N) and spike (S) protein of the coronavirus. The presence of IgG to spike (S) protein in the blood may indicate the presence of protective immunity, which is formed both after the disease and after vaccination. The preservation of IgG-class antibodies makes it possible to identify people who have been infected in the past, recovered from the disease or become immune. The test allows you to track the dynamics of antibody levels, including after vaccination.