A positive (or Reactive) Covid-19 antibody test means that the person being tested has been exposed to Covid-19. A negative (or Non-Reactive) test means that the person being tested has not been exposed to Covid-19.
Antibodies are the body’s way of defending itself against disease. With many diseases, scientists know the effect of antibodies. Some diseases, such as chickenpox, cause the body to produce antibodies that last for 20 years or more. Other diseases, such as the seasonal flu, cause the body to produce antibodies that, in some cases, help make the symptoms somewhat less the next time the person gets the seasonal flu. They do not keep the person from getting the flu again. Other antibodies produce effects that lie somewhere between these two extremes.
One problem with Covid-19, is that it is so new that there has not been time for scientists to research how much if any, difference, Covid-19 antibodies make in lowering a person’s chance of getting Covid-19 again, or of having an easier time if they get it.
While it would be great to discover that Covid-19 antibodies act like the antibodies for chickenpox, the fact is that scientists just aren’t sure. Until more is known, patients who test positive for Covid-19 antibodies need to realize that the test does not prove that they are immune from getting the disease again. They still need to practice social distancing and masking, and they still need to be aware of possible Covid-19 symptoms if they get sick.
As time passes and there is time for more research, the effect of Covid-19 antibodies will be studied and their effect will be better understood.