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Max Minute: What Antibody Tests Can And Cannot Tell About A Coronavirus Infection

By Dr. Max Gomez

NEW YORK (CBSNewYork) - Antibodies have become the subject of much hope and controversy in the fight against the COVID-19 coronavirus pandemic.

An antibody test looks for very specific proteins that your immune system makes in response to an infection, whether it's bacteria, flu, HIV or COVID-19 coronavirus.

A corona antibody test looks in a drop of blood from a finger stick for the antibodies against that virus.

Depending on which type of antibody the test looks for, it can tell if you have an ongoing infection or an infection that you've recovered from, and that's key. If you had the infection and recovered, then you are likely immune to re-infection by the coronavirus and could be safe to return to work - but that's an assumption.

In some diseases, while the body makes antibodies, those antibodies aren't actually protective against that disease. It remains to be definitively proven that corona antibodies actually protect the patient immune against re-infection.


Another qualifier is that it takes about a month for the body to develop enough antibodies for the tests to be reliable It's not useful to tell if you've been exposed or infected but are still in that month-long period before you make sufficient antibodies.

Finally, we have to be careful about the accuracy of the myriad tests being sold right now. A false-positive test, for example one that detects one of the coronaviruses that cause the common cold, could lead someone to believe they are immune to COVID-19 and are safe to return to work when in fact they could be at risk for a deadly infection.

For the top questions people have been asking about the coronavirus, visit, and go to to submit your question.

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