When our immune system comes into contact with the Coronavirus or when you receive a Covid-19 Vaccine, it triggers an immune response to develop antibodies. There are several type of antibodies we can test for but how do you know if you had been infected with Covid19 or if the vaccine worked?
The test is mostly determined with serum which comes from a blood sample which will be then used to check if you have any of the Immunoglobulins such as IgG, IgM and IgA in your body. This may help your doctors to advise you if you had a Covid-19 infection before or produced antibodies to the the Covid-19 vaccination.
Antibodies are proteins made by the immune system to fight infections from microorganisms such as viruses to help to ward off future infections and reduce the risk of hospitalisation . Antibodies can take days or weeks to develop in the body following exposure to a SARS-CoV-2 (COVID-19) infection and it is unknown how long they stay in the blood.
If you have a positive test result for a SARS-CoV-2 antibody test, it is possible that you have recently or previously had COVID-19. There is also a chance that the positive result is wrong, known as a false positive. False positive tests may occur:
Because antibody tests may detect coronaviruses other than SARS-CoV-2, such as those that cause the common cold.
When testing is done in a population without many cases of COVID-19 infections. These types of tests work best in populations with higher rates of infection.
A positive antibody test does not necessarily mean you are immune from SARS-CoV-2 infection, as it is not known whether having antibodies to SARS-CoV-2 will protect you from getting infected again. It also does not indicate whether you can infect other people with SARS-CoV-2.
A negative result on a SARS-CoV-2 antibody test means antibodies to the virus were not detected in your sample. It could mean:
You have not been infected with COVID-19 previously.
You had COVID-19 in the past but you did not develop or have not yet developed detectable antibodies. It is unknown if all infected individuals will develop a detectable antibody response.
The result may be false negative. This occurs when the test does not detect antibodies even though you may have specific antibodies for SARS-CoV-2.
You may be immunocompromised
Antibodies develop over time and It will take around two weeks to develop this immune response to COVID-19 or its vaccine, so do give some time for your body to respond before testing to detect the “right” antibody.