The human organism needs some time (usually around 2 - 3 weeks) to produce antibodies against SARS-CoV-2 . Antibody tests are intended to support the diagnosis of a SARS-CoV-2 infection and complement direct detection of the pathogen (PCR). Serology can also be used to collect epidemiological data, which is especially important in the case of this largely unexplored new infection.
IgA and IgG antibodies have a sensitivity of 89 - 100%. Specificity of the IgA antibodies is 87.5 - 100%, and 83.5 - 97.5%  for IgG antibodies. The antigen (S1 domain) used in the test is particularly appropriate for the serological detection of SARS-CoV-2 antibodies as it is more specific than the N or full-length S protein please see the scientific paper “SARS-CoV-2 antibody responses in COVID-19 patients”, for further details, and the other references provided. The test is CE certified, IVD registered and validated.
In order to:
Please note that the test for IgA antibodies in particular is not suitable for screening asymptomatic subjects