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SBC Testing for SARS-CoV-2 Antibodies

July 23, 2020 at 9:27 am
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SBC is now testing all donations for antibodies to SARS-CoV-2 and posting results on donors’ online portals at sbcdonor.org. Read below to find out more about the antibody test and its results. If you have additional questions, please reach out to SBC Donor Relations at sbcsupport@stanford.edu or 650-736-7786.

 

Is SBC testing donations for antibodies?

Yes! Due to donor interest as well as a need for SBC to identify more potential COVID-19 convalescent plasma (CCP) donors, SBC is excited to be performing SARS-CoV-2 antibody testing on each donation, as of July 30.

 

Does receiving the antibody test change my donation experience in any way?

No. The antibody test will not require any extra blood to be drawn and will not add to your donation time.

 

How long will SBC be offering the antibody test, and can I receive it more than once?

While we are uncertain how long we will be offering the test at this time, we are anticipating testing each donation at least through the end of August 2020. Because antibody status can change over time, we will be testing each donation, even if you have already donated and been tested previously. (Note that this will likely only apply to platelet and plasma donors, who have very short deferral periods between donations.) We will be sure to communicate any updates to this timeline on this page in the future.

 

Can I receive antibody testing even if I’m not eligible to donate?
Because the primary purpose of our organization is to collect blood to help local patients, we are only performing antibody testing on those who come in to donate blood. However, if you come in with the intention of donating and are deferred during the donation screening process, we will still be able to draw one tube from you to test for antibodies, assuming that you are not deferred for any symptoms of or recent exposure to illness. If you know that you are not eligible to donate at this time, we ask that you please help us preserve our time and resources and seek testing through your primary physician instead.

 

Where can I see the results of my antibody test?

The results of this test will be made available on your online donor portal, sbcdonor.org, under the “Test Results” section. Results should be posted within two weeks of your donation. If they do not populate by this time, please contact SBC Donor Relations at sbcsupport@stanford.edu or 650-736-7786.

 

Is an antibody test the same as a diagnostic test for COVID-19?

This is not a diagnostic test for COVID-19; it is meant to determine whether you may have had previous exposure to SARS-CoV-2, the virus known to cause COVID-19. Additionally, a positive test result does not guarantee immunity from COVID-19. For a full assessment of previous exposure to SARS-CoV-2, please consult your primary physician.

 

What do my results on the SARS-CoV-2 antibody test mean?

POSITIVE:

A positive result on the antibody test means that you may have had previous exposure to the virus. Based on your antibody levels and other eligibility criteria, you may be contacted by our Special Donations team to donate COVID-19 convalescent plasma (CCP), which has the potential to save the lives of hospitalized COVID-19 patients. Learn more our CCP program here.

Note that a positive result does not, however, mean that you necessarily have immunity to COVID-19, nor does it mean that you cannot spread COVID-19 to others. Furthermore, a positive result may be a false positive. Regardless of your results, if you are concerned about COVID-19 exposure, you should talk to your physician and continue to follow public health guidelines and take appropriate steps to ensure the health of yourself and those around you.

NEGATIVE:

A negative result on the antibody test means that SARS-CoV-2 antibodies were not detected in your blood. This does not, however, mean that you necessarily have never been exposed to the virus, since antibodies tend to decrease in the blood over time. If you are concerned about COVID-19 exposure, you should talk to your physician and continue to follow public health guidelines and take appropriate steps to ensure the health of yourself and those around you.

 

Does a presence of antibodies mean that I am immune to reinfection from COVID-19?

No! These are active areas of investigation among the scientific and medical communities presently. A positive result does not mean that you necessarily have immunity to COVID-19, nor does it mean that you cannot spread COVID-19 to others. Regardless of your results, if you are concerned about COVID-19 exposure, you should talk to your physician and continue to follow public health guidelines and take appropriate steps to ensure the health of yourself and those around you.

 

What is a false positive or false negative result?

A false positive result means that the antibody test indicated you had antibodies when you did not; conversely, a false negative result means that the antibody test indicated that you did not have antibodies when you did. While we love to paint science and medicine as straightforward and infallible fields, the truth is that no medical test will be accurate 100% of the time. Thankfully, by performing controlled tests and validations, we can limit the amount of false results we receive.

If you feel your results may be false given the context of your specific situation (e.g., you tested negative for antibodies but are nearly certain you recently recovered from COVID-19), we encourage you to check in with your primary physician to discuss the potential value in taking a repeat test.

 

I tested positive for antibodies before, but now I am testing negative. Why is that?

There could be many reasons for this. First, different tests may have slightly different performance characteristics; for anyone who may be weakly positive on one test, they may easily be negative on another. Secondly, antibody levels can wane over time in many people, so it may be that on the initial test you had a significant number of antibodies, but by the time the second test was performed, those antibodies had decreased. Thirdly, every test has a small but real possibility of having false positive or false negative results; this is why it is important to consult your physician if you have any doubts as to the accuracy of your results so they can be contextualized.

 

How can I be considered for the COVID-19 convalescent plasma (CCP) program at SCB?

Thank you for your interest in helping save the lives of COVID-19 patients! f your results show that you tested positive for antibodies and you meet additional qualifications that would make you a great candidate for COVID-19 convalescent plasma donation, you will be contacted by our Special Donations team. For more information on our program, visit our CCP page here.