Should I Get Tested for COVID-19 Antibodies?
There has been a lot of public discussion about “testing” for COVID-19. While there is great need for such testing, the truth is the science is not there yet.
Spoiler alert: Antibody testing is not ready for commercial use YET – despite what you are hearing, and what we all want to believe. Why? We don't yet know whether a ‘positive’ test results means you actually have antibodies to COVID-19! This is known as a FALSE POSITIVE and is based on the specificity of the test – commercial tests do not have specificity values for the general healthy population – i.e. someone like you.
Current Recommendations
I am recommending you DO NOT get tested for antibodies using the rapid diagnostic finger-stick test. I am open to testing for antibodies using whole blood as this is the current gold standard, but that option is currently only available in research studies (e.g. Stanford or the upcoming UC-Berkeley studies).
Next Steps
I am working closely with lab and research scientists at UC-Berkeley, UCSF, and Stanford to identify an accurate diagnostic test. Once a reliable and accurate commercial test becomes available, I will notify you immediately and make it available to you and your family.
COVID-19 Antibodies Testing Background
The emerging commercially available rapid diagnostic antibody tests (RDTs) are not yet validated to know whether a positive test result in someone such as yourself living a healthy life in the general population actually has antibodies to COVID-19 (i.e. unknown test specificity). We think that a negative test result is fairly accurate at predicting you did not develop antibodies to COVID-19 (i.e. known as test sensitivity); however, again we are not confident yet that a positive test result accurately predicts that you do in fact have antibodies to COVID19. That is, the rate of false positive test results in unknown in these tests. We anticipate that in the next 1-3 months such data will become available.
What is required to validate these tests?
Sensitivity Testing – this is fairly well established and ensures everyone with the disease gets a positive test result (minimizing the false negative rate). Take PCR positive patients and test them over time to figure the timing and thresholds for a positive antibody test results using whole blood and finger stick.
Specificity Testing – take patients without symptoms, confirm they are PCR negative, draw whole blood and finger-stick, then quantify how many have negative and positive test results. Gold standard is the results of the whole blood ELISA testing for negative test results.
What should I do with the information?
Whether or not a positive COVID-19 antibody test result indicates immunity and for what duration remains to be fully clarified.
Thank you to Dr Benardita Mendez PhD and Mary Gutierri PhD regarding the challenges validating and scaling antibody testing.
