These are the antibodies against SARS-Cov-2. After infection with Covid virus, the body immediately starts fighting with the virus. This means that, the production of antibodies are increasing. In all types of respiratory viruses, the first antibody is IgA, produced by the secretory plasmablast cells of nasopharyngeal system. Some researches showed that, IgA serum concentrations rise in the first 3 days of the onset of symptoms and persist several weeks in saliva. It is also reported that, serum IgA was more potent than IgG in neutralizing SARS-CoV-2.(Sterlin et al; Science Translational Medicine, Vol13;577,2021). IgM antibodies in viral infections appear 7-10 days after the onset of symptoms. A positive IgM test, indicates that the patient has recently been in contact with the virus and your immune system has started responding the infection. Science has not yet defined the pattern of the immune response to the infection but at this time (2020), it is only posssible to say that it remains in the blood 15-43 days (Huang et al,Lancet-2020,Feb 15;395(10223):497-506).This early rise is then followed by the production of IgG antibodies. SARS-CoV-2 Ig G types of immunglobulins are detected in the blood of infected patients as an adaptive immune response towards the virus just after the IgM ‘s. Therefore, IgG antibodies should not be diagnosed for an acute infection.Test may be positive after several weeks of seroconversion. It is not yet known how long the IgG positivity in blood persists (Zou L. et a, N. Engl.J Med-2020 Mar 19;382(12):1177-9) When IgM turns into IgG antibodies, we can talk about Total Antibodies. This may be the combination of the two or only IgG antibodies which are the latest produced main antibodies to fight against the virus. Vaccination has started immunizing people all around the world and antibody measurements have gained importance. It is still not clear after how many doses of vaccine immunization will be obtained and how long this will last, but the antibodies measured , will be total antibodies. Conventional vaccines of inactivated virus and antibodies after a Covid infection, will surely reflect total antibodies but mRNA based vaccines , (Pfizer, Biontech ,Moderna, Johnson and Johnson and others), the body will be producing Spike antibodies (the part of the virus from where it enters pulmonary cells). Therefore, the antibodies to be tested is Spike Antibodies. It is better to ask the patient about his past Covid infection and his type of vaccine to decide which antibody test would reflect his immune status .
Interpretation:As we all need antibodies to fight Sars-CoV-2 infection, high levels would be what we need to have but it is still not clear what antibody levels will be protecting us or when the levels will drop to have other vaccinations. All the immunisation issues are yet to be investigated and approved by scientific authorities.
Sample: Arm vein blood. Nonfasting
Working day: Everyday
Result Time: 4 hours
