There are two kinds of test. The one with the nasal swab detects an infection that is active at the time of the test.
The other kind is a blood test for antibodies. It detects if you caught the virus long enough in the past for the antibodies to build up. A person with a positive antibody test may, or may not, still have the virus.
After a while, the antibodies go away So if you had it last fall the antibodies might be gone by now; no one is sure how long they last. Even if you had antibodies and they have faded away, there are other parts of the immune system that will be ready to fight the virus. How these other types of immunity last isn't known yet. |
