What is an antibody test?
The antibody test (sometimes called a serology [blood] test) determines the types of antibodies present in the blood. Antibodies are blood proteins produced by healthy patients in response to and counteracting specific foreign materials (antigens). Antibodies chemically combine with substances that the body recognizes as alien; Such as bacteria, viruses, and foreign proteins in the blood. Each antibody attacks one particular antigen and helps to clear the foreign material from the patient’s bloodstream.
Is an antibody test different than a swab test from my nose or mouth?
Yes. Nasal or throat swabs are generally used to obtain the pathogen itself (or its genetic components) and used for molecular tests. Because antibodies are present in your bloodstream, antibody tests require just a small sample of blood. This may require venipuncture (blood drawn from the arm into a tube for delayed analysis) or a fingerstick, for a test that can produce rapid results, in 15 minutes or less. Our tests utilize two small drops of blood from a single fingerstick. Antibody testing is improved over nasopharyngeal swab testing by the fact that antibodies are more uniformly present in blood sampling.
Are Antibody Tests FDA Approved? Do They Need To Be?
COVID-19 Rapid Blood Tests for use by laboratories and healthcare workers at the point-of-care, has not been approved by the FDA. The FDA does not intend to object to the development and distribution of serology tests by commercial manufacturers or laboratories that identify antibodies to SARS-CoV-2 where 1) the test has been validated, 2) notification has been provided to the FDA, and 3) information along the lines of the following is included in the test report:
- These test have not been reviewed by the FDA.
- Negative results do not rule out SARS-CoV-2 infection, particularly in those who have been in contact with the virus. Follow-up testing with a molecular diagnostic test should be considered to rule out infection in these individuals.
- Results from antibody testing should not be used as the sole basis to diagnose or exclude SARS-CoV-2 infection or to inform infection status.
- Positive results may be due to past or present infection with non-SARS-CoV-2 coronavirus strains, such as coronavirus HKU1, NL63, OC43, or 229E.
This policy is limited to such testing in laboratories or by healthcare workers at the point-of-care. The tests are offer are manufactured by FDA-approved manufacturers and are in compliance with the FDA’s criteria.