Serological tests for Covid-19 detect whether one has come in contact with Covid-19 and thus whether the organism has developed specific antibodies to SARS-CoV-2 (Covid-19 or Coronavirus). They detect the presence of circulating IgM and IgG antibodies in the blood that are an indicator that the immune system has reacted to Covid-19 infection and therefore the organism could potentially have developed immunity to the virus.
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