IgM and IgG / SARS-CoV-2 Serology (COVID-19)
The blood test should be taken 7 days after exposure to the virus or at least 4 days after the onset of the first symptoms. The scan cannot detect an infection in the initial phase of contagion. This means that before this initial phase of contagion, the antibodies cannot test positive. There are four possible Covid-19 antibody test interpretation results:
1) IgM negative, IgG negative:
There is no evidence of a current or past infection. If there is any doubt of infection, despite this initial result, a new analysis can be performed a few days later.
2) IgM positive, IgG negative:
The result indicates or suggests infection in the initial stage of the disease. In some cases without clinical reality of the asymptomatic patient.
3) IgM positive, IgG positive:
The patient is in the intermediate phase of the infection. It is reasonable to think that the possibility of infecting others is low.
4) IgM negative, IgG positive:
The patient is cured and he is no longer contagious. A level of immunity to Covid-19 is normally achieved. But it is impossible to say for how long and to what extent!
Blood immuno-serology (viral serologies)
SARS-CoV-2 (COVID-19) serology
Titer of anti-COVID-19 IgG (threshold of positivity: titer equal to or greater than 10)
Positive serology. Profile compatible with immunization against SARS-CoV-2. The presence of the antibodies detected by currently available tests does not determine whether the immunity is protective. Given the still limited evaluations of the test, the results should be interpreted with caution and depending on the clinical context. False positives cannot be completely ruled out.