• Assure COVID-19 FDA EUA Letter

• Assure COVID-19 Patient Fact Sheet

COVID-19 Antibody Tests 

This page contains information to help you understand the risks and benefits of a COVID-19 antibody tests. After reading this page, if you have questions or would like to discuss the information provided, please talk to your healthcare provider. For the most up to date information on COVID- 19 please visit the CDC Coronavirus Disease 2019 (COVID-19) webpage: https://www.cdc.gov/COVID19.

What is an COVID-19 Antibody Test? A COVID-19 antibody test is designed to detect antibodies to SARS-CoV-2, the virus that causes COVID-19. These antibodies can be produced even if a person has few or no symptoms during the infection. It can take several days after an infection for the body to product antibodies. 

Antibodies developed in response to an infection in some cases protect the individual from been re-infected for a period of time. We do not yet know whether this is true also for COIVD-19 and if having antibodies to SARS-CoV-2 will prevent against secondary infection. As of today, there have been very few cases of documented secondary infection. Therefore even if you have recovered and have antibodies, there is a chance that you still have the virus and you can infect others, it is still critical to keep taking measures to avoid getting infected again and/or spreading infection.

Results from this test should not be used to diagnose or exclude acute SARS-CoV-2 infection. Results are not intended to be used as the sole basis for patient management decisions. Test results should be interpreted in conjunction with clinical observations, patient history, epidemiological information, and other laboratory findings. 

What are the known and potential risks and benefits of performing test?

Potential benefits include:

•       The results, along with other information, can help your doctor make informed recommendations about your care.

•       The results of this test may help limit the spread of COVID-19 to your family and others in your community.

Potential risks include:

•       Possible discomfort or other complications that can happen during sample collection.

•       Possible incorrect test result (see below for more information).

What does a Positive Antibody Test Mean? A positive antibody test means that antibodies were detected in your blood sample. This could mean that:

• You have been infected with SARS-CoV-2 at some point in the past, or

• Rarely, you have developed antibodies from past or present infection from other corona viruses (non-COVID-19) such as HKU1, NL63, OC43, or 229E, that the laboratory test cannot distinguish from the antibodies developed in response to SARS-CoV-2.

• The test has several possible results. Depending on the result, it may be more likely that you have COVID-19 and that you may need isolation to avoid spreading the virus to others. Other results may indicate you were infected previously. Your healthcare provider will work with you how to determine how best to care for you based on the test results along with other factors of your medical history, and your symptoms, possible exposures, and geographic location of places you have recently traveled. There is also the small chance that this test can give a positive result that is wrong (a false positive result). Even a high-performing antibody test when used in a population without many cases of COVID-19 infection may produce as many or more false results as true results because the likelihood of finding someone who has been infected is very small.

What does a Negative Antibody Test Mean? A negative antibody test means that antibodies were NOT detected in your blood sample.

• Negative results do not preclude acute SARS-CoV-2 infection. If acute infection is suspected, direct testing (e.g., swap) for SARS-CoV-2 is necessary.

• A negative result can occur: If there has not been enough time for antibodies to develop or to reach a sufficient level for the test to be able to detect them. For example if the patient blood was collected during the early phase of illness or due to a decline in antibody titer over time. Or if the immune response is depressed as in elderly, immunocompromised, or immunosuppressed individuals. 

• If symptoms persist and the result is negative, it is recommended to re-sample the patient a few days later.

• A negative test result means that the antibodies to the virus that causes COVID-19 was not found in your sample. However, it is possible for this test to give a negative result that is incorrect (false negative) in some people with COVID-19. A negative result may occur if you are tested early in your illness and your body hasn’t had time to produce antibodies to infection. IgM and IgG antibodies may take 1 to 3 weeks to develop after infection (for more info visit the CDC). This means that you could possibly still have COVID-19 even though the test is negative. If this is the case, your healthcare provider will consider the test result together with all other aspects of your medical history (such as symptoms, possible exposures, and geographical location of places you have recently traveled) in deciding how to care for you. It is important that you work with your healthcare provider to help you understand the next steps you should take.

Does having antibodies mean that I am immune to COVID-19? Antibodies are proteins that the body produces in response to infections. They are produced by the human body in response to viral infections. For many viruses the presence of antibody provides immunity to the disease. Higher concentration of antibody (know as higher titers) can lead to immunity. Vaccination typically result in the production of antibody that provide immunity. The antibodies can be produced even if a person has few or no symptoms during the infection. However, as COVID-19 is a new virus, we currently do not know if antibodies provide immunity. It is not known how long antibodies to SARS-CoV-2 will remain present in the body after infection. It is not known whether having antibodies to SARS-CoV- 2 will protect you from getting infected again or help reduce the severity or duration of a future COVID-19 infection. Regardless of your test result, you should continue to follow CDC guidelines to reduce the risk of infection, including social distancing and wearing masks. As alway please refer to your health care provide, FDA and CDC for further informations.

What type of COVID-19 antibody tests are used by ADX Diagnostic Lab? The COVID-19 antibody offered by ADX Diagnostic Lab are designed to detect the presence of antibodies against the virus, SARS-CoV-2, that causes COVID-19. An antibody test may not be able to show if you have a current infection, because it can take 1-3 weeks after infection to make antibodies.

How accurate are the antibody tests used by ADX Diagnostic Lab? All our antibody tests have a demonstrated Positive Percent Agreement (Sensitivity) of 100%, and Negative Percent Agreement (Specificity) greeter then 98.9%. We are using both a laboratory developed test (known as LDT) and a CLIA-waived Test (Assure COVID-19 IgG/IgM Rapid Test Device). You can download more info about the Assure COVID-19 IgG/IgM Rapid Test here: Assure COVID-19 FDA EUA Letter, Assure COVID-19 Patient Fact Sheet.

How Does the Test Work? We offer two type of tests. One is performed by drawing a small amount of blood (smaller than half teaspoon) by venipuncture. We also offer a test which require only a small finger prick (Assure COVID-19 IgG/IgM Rapid Test Device). The collected blood is then tested to detect the presence of COVID-19 Antibodies (IgG or IgM). These tests are designed to detect antibodies against the N-protein or Spike protein of SARS-CoV-2, and can detect either the total antibodies IgM and IgG or either one.  

Is this test FDA-approved or cleared? The FDA has authorized the use of antibody test under Emergency Use Authorization (Under section 564 of the Federal Food, Drug, and Cosmetic Act). The Assure COVID-19 IgG/IgM Rapid Test Device used by ADX Diagnostic Lab has received EUA authorization from the FDA. When there are no FDA-approved or cleared tests available, and other criteria are met, FDA can make tests available under an emergency access mechanism called an Emergency Use Authorization (EUA). The EUA for this test is supported by the Secretary of Health and Human Service’s (HHS’s) declaration that circumstances exist to justify the emergency use of in vitro diagnostics for the detection and/or diagnosis of the virus that causes COVID-19. The EUA will remain in effect (meaning this test can be used) for the duration of the COVID-19 declaration justifying emergency of IVDs, unless it is terminated or revoked by FDA (after which the test may no longer be used). In addition, the ADX Diagnostic Lab is CLIA Certified High Complexity laboratory and it is authorized under the Clinical Laboratory Improvement Amendments of 1988 (CLIA), 42 U.S.C. §263a, to perform high complexity tests, including the Assure COVID-19 IgG/IgM Rapid Test and the ADX Diagnostic Lab’s developed antibody test, the Rapid C2T Total Ab (IgG/IgM) Card.