Antibody tests are medical tests that check for the presence of antibodies in the blood. Antibodies are proteins produced by the immune system in response to infections, including viruses like COVID-19. These tests can help determine if a person has been exposed to a specific pathogen, even if they never showed symptoms. The results of antibody tests can provide valuable information about immunity and past infections. However, they are not used to diagnose current infections, as antibodies take time to develop. It's important to consult healthcare professionals for accurate interpretation of test results and their implications for health.