How long do antibodies last?

Antibodies are proteins made by the immune system that recognise features of a virus. A test may detect antibodies from infection, vaccination, or both, depending on the test and its timing. A positive result does not provide a precise expiry date for protection, and a negative result does not prove that no immune memory exists. Protection also involves immune cells that are not measured by many routine antibody tests. Antibodies do not diagnose the cause of current symptoms on their own.

Do not use an antibody result as permission to ignore symptoms or protective advice. If you develop fever, cough, fatigue, or loss of taste or smell, follow testing and infection-control guidance that applies to your situation. Keep recommended vaccinations up to date when advised, particularly if you have a condition or treatment that affects immunity. Bring the test name, result, and date to a clinician if you need help interpreting it.

Seek urgent help for difficulty breathing, chest pain, new confusion, inability to stay awake, or blue or grey lips, regardless of an antibody result. Arrange medical advice if symptoms persist, worsen, or return after improvement. People with weakened immunity should ask promptly about symptoms after a possible exposure because antibody testing may not reflect their full protection.

Ask what your specific test detects, whether the timing makes the result meaningful, and whether vaccination or previous infection could explain it. Ask which preventive steps still apply and whether your medical history changes the advice.