Users' questions

What is the difference between the IgM and IgG antibodies tests for COVID-19?

What is the difference between the IgM and IgG antibodies tests for COVID-19?

Both SARS-CoV-2 IgM and IgG antibodies may be detected around the same time after infection. However, while IgM is most useful for determining recent infection, it usually becomes undetectable weeks to months following infection; in contrast, IgG is usually detectable for longer periods.

How long can COVID-19 antibodies be detected in blood samples?

Antibodies may be detected in your blood for several months or more after you recover from COVID-19.

What does a negative antibody test for COVID-19 mean?

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.

Does an antibody test diagnose an active COVID-19?

Antibodies can take several days or weeks to develop after you have an infection and may stay in your blood for several weeks after recovery. Because of this, antibody tests should not be used to diagnose an active coronavirus infection.

Will I be able to return to work without having an antibody test for COVID-19 done?

The requirements for returning to work may be determined by your employer or your state and local governments. Ask your employer about your workplace’s criteria for returning to work and any actions your employer will be taking to prevent or reduce the spread of COVID-19 among employees and customers.

What is the COVID-19 antibody test?

An antibody test looks for antibodies that are made by the immune system in response to a threat, such as a specific virus. Antibodies can help fight infections. Antibodies can take several days or weeks to develop after you have an infection and may stay in your blood for several weeks after recovery. Because of this, antibody tests should not be used to diagnose an active coronavirus infection. At this time, researchers do not know if the presence of antibodies means that you are immune to the coronavirus in the future.

What does a positive antibody test for COVID-19 mean?

If you have a positive test result on 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.

What does a negative antibody test for Covid-19 mean?