We Are Blood COVID-19 Antibody Testing

Posted: Oct 27, 2020 | Category: Latest Articles

What does it mean if I receive a positive antibody test?

If you had past symptoms suggestive of COVID-19 or have been exposed to persons with the COVID-19 infection, then positive test results suggest you may have been infected with COVID-19 and may qualify for convalescent plasma donation. If you were not sick or do not know if you were exposed, it is harder to know what the test results mean. Either way, continue to practice caution in the community and protect yourself and others from possible exposure.

  • If I test positive for antibodies to COVID-19, does that mean I could still be infectious with the disease and be harmful to others?

All indications right now are that antibody means recovery after infection. We have no reason to believe someone would be infectious while having antibodies. The evidence supports a very small window of infectiousness, starting a couple of days before symptoms and not lasting long after fever is gone.

  • If my blood tests positive, will the plasma be given to a current COVID-19 patient?

If you qualify for convalescent plasma donation, the plasma portion of your blood may be used to treat a current COVID-19 patient, based on hospital demand.  We are blood staff may contact you if additional information is needed to determine if you qualify.

What does it mean if I receive a negative antibody test?

If you have felt well and have not been around anyone that has been diagnosed with COVID-19, then a negative test most likely means you have not been infected, or that your antibodies may have decreased to undetectable levels. Additionally, there are many reasons a false-negative test result could occur, including the fact that this is an investigational test (e.g. newly developed and not U.S. Food and Drug Administration (FDA)-approved). If the screening antibody test is negative, additional antibody testing will not be performed and you would not qualify for convalescent plasma donation. You would continue to be eligible to donate blood products for the community! Continue to practice caution in the community and protect yourself and others from possible exposure

Will my antibody test come back positive because I received the COVID-19 vaccine?

The antibody tests we perform will not show that you are positive for antibodies after receiving a COVID-19 vaccination. Even if the vaccine was successful. The tests we use detect antibodies to different parts of the virus.

What is the difference between a diagnostic test and an antibody test? 

A diagnostic test looks for the presence of the actual virus. The antibody tests are not designed for the diagnosis of active infection. These tests are designed to detect antibodies to SARS-CoV-2, the virus that causes COVID-19. These tests may be an indicator that an individual has been exposed to coronavirus. More experience is needed with the test to know whether it is specific for SARS-CoV-2 coronavirus and is not picking up past exposure to other types of coronaviruses, such as colds. That is why a positive antibody result should not be used as proof of immunity to COVID-19. Experts also do not yet know if having SARS-CoV-2 antibody protects you from re-exposure to COVID-19.

Do I have to give blood to receive the COVID-19 antibody test?

Yes. We Are Blood is offering the tests to help identify and qualify convalescent plasma donors. Successful donations will be tested. The COVID-19 antibody test is performed in addition to all FDA-required testing to ensure patient safety.

Can you test my blood donation for active infection with COVID-19?

No. Please do not donate blood if you are sick or think you were recently exposed. This test is not a COVID-19 diagnostic test. If you believe you could have COVID-19 or another illness, please contact your health care provider. Donors are required to feel well and healthy at the time of donation, and to wait at least 14 days after potential exposure or infection symptoms resolve before attempting to donate blood for the community.

Does We Are Blood test all blood donors for active infection of  COVID- 19?

No. Scientific evidence at this time has not shown any risk of transmission of any coronavirus through blood transfusion. The viruses that we test for are those that can potentially be spread through blood transfusion. COVID-19 is a virus that is spread through respiratory droplets and not through donated blood.

If I gave blood before the testing began, will my blood be tested?

No. Only successful donations beginning Wednesday, October 28th, and moving forward will be tested, for the COVID-19 antibodies.

May I ask that my blood not be tested?

No. All donations beginning Wednesday, October 28th will be tested for coronavirus antibodies to meet updated FDA requirements for convalescent plasma qualification. (Click to view FDA requirements)


Convalescent plasma is a plasma product collected from individuals who have recovered from the COVID-19 infection.   This product contains a high level of antibodies from the recovered donor.  The plasma product has FDA Emergency Use Authorization for the treatment of hospitalized COVID-19 patients.  Donors who have received COVID vaccine must meet additional criteria to qualify for convalescent plasma donation.

Will the test results be shared with anyone else besides the donor?

No. Antibody tests are not used to diagnose COVID-19. Only diagnostic test results are reportable to health authorities.

  • When will the test results be available and how can blood donors access their results?

Blood donors will receive the results through the We Are Blood website on their donor portal – a personal page with your login and a password that you establish and that is intended for your access. The results will only be posted there and will be accessible approximately 7 days after your blood donation. weareblood.org/donor/login/.

What tests are We Are Blood using?

FDA Convalescent Plasma qualification criteria require two separate antibody test that has received FDA Emergency Use Authorization, to qualify a donor for convalescent plasma donation. Only samples that are positive on the screening antibody test and qualified as high titer on the second antibody test can be used as convalescent plasma.  Any sample that tests negative on the screening antibody test will not have additional testing and will be reported as negative and would not qualify the donor for convalescent plasma donation.

Previous convalescent plasma donors who no longer qualify for convalescent plasma donation based on antibody test results remain eligible to donate as regular blood or platelet donors.

Antibody test results (positive or negative) do not impact a donor’s future eligibility for regular blood donation.

The Roche Diagnostics Elecsys® Anti-SARS-CoV-2 serology test* is the initial screening test performed. According to Roche, it is designed to detect antibodies in people who have been exposed to the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that causes the COVID-19 disease.

The Ortho VITROS Anti-SARS CoV-2 IgG serology test* will be performed if the Roche test is positive. According to Ortho, it is intended for use as an aid in identifying individuals with an adaptive immune response to SARS-CoV-2, indicating recent or prior infection.

*Note: This test has not been reviewed by the FDA. It has received FDA Emergency Use Authorization.

How much do the tests cost?

The COVID-19 antibody tests offered by We Are Blood to its volunteer donors are free and performed on successful donations.