Corona Serology test
What is serology test (Antibody test)?
- Antibody tests check your blood by looking for antibodies, which may tell you if you had a past infection with the COVID-19 virus or are currently carrying the virus asymptomatically. Antibodies are proteins that help fight off infections and can provide protection against getting that disease again (it indicates if you have developed immunity against this virus).
What do your results mean?
- In general, a positive antibody test is presumed to mean a person has been infected with SARS-CoV-2 at some point in the past. It does not mean they are currently infected.
- Antibodies start developing within 1 to 3 weeks after infection.
- A positive test result shows you may have antibodies from an infection with COVID-19. Having these antibodies may provide protection from getting infected with the virus again but we still don't know for how long this protection may last.
- You should continue to protect yourself and others since you could get infected with the virus again.
- You may test positive for antibodies even if you have never had symptoms of COVID-19. This can happen if you had an infection without symptoms, which is called an asymptomatic infection.
- If you test negative for the virus then you either have never had COVId-19 or you haven't developed antibodies yet since it usually takes 1 - 3 weeks to develop antibodies.
- Regardless of whether you test positive or negative, the results do not confirm whether or not you are able to spread the virus that causes COVID-19. Until we know more, continue to take steps to protect yourself and others.
Anti-SARS- CoV-2 Immunoglobulins (Seroconversion)
- Seroconversion has been observed as early as within 5 days after symptom onset for Immunoglobulin M (IgM) and withing 5-7 days for IgG.
Based on still scarce data, anti-SARS-CoV-2 IgA seem to appear at 3-6 days post-symptom onset.
- Depending on the applied method seroconversion is observed after a median of 10-13 days after symptom onset for IgM and 12-14 days for IgG.
- Maximum seroconversion occurs at 2-3 weeks for IgM, at 3-6 weeks for IgG, and at2 weeks for total antibodies.
- Whereas IgM seems to vanish around week 6-7, high IgG seropositivity is seen at that time.
- Levels and chronological order og IgM and IgG antibody appearance are highly variable, supporting detection of both antibodies simultaneously.