Antibody Testing

We currently offer two forms of antibody testing: the standard Antibody IgG test and the more advanced Spike Protein Antibody test, both of which are blood tests.

Our testing includes a visit from a healthcare professional to your home for the blood test. The test specimen is delivered on the same day to a CLIA licensed laboratory that has been authorized by the FDA under an EUA for antibody testing.

We do not offer rapid, point-of-care antibody testing at this time.

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Antibody Test (IgG) - $150

The test detects if you have had prior exposure to or infection with COVID-19 and have built antibodies to the virus. It should be performed 3-4 weeks after symptom onset. For most viral illnesses, a positive antibody means prior exposure to a virus and possible immunity to future infection. As COVID-19 is a novel infection, it is unclear if a positive antibody test infers immunity. This test offers a Positive/Negative result only.

Spike Protein Test - $150

This test is used in people who have received any vaccine. The test potentially identifies antibodies created by you in response to previous COVID-19 infection, or potentially a spike vaccine against the COVID-19 virus. The result is a quantitative titer value for antibody response (numerical result).

Regardless of your results, you should continue to exercise universal precautions such as social distancing, quarantining, frequent hand washing, wearing of a mask or face cloth in public, and other CDC guideline recommendations. Keep in mind that COVID-19 is a new infection, and it is unclear if a positive antibody definitively infers immunity.
Insurance Coverage: The self-pay fees listed are for a combination plan of consultation, travel to your location and health data communication only. Neither the Practice, nor its Staff, participates in any health insurance or HMO plans. Therefore, we will not bill any insurance plan or prepare invoices for Patient’s to submit for reimbursement.
If you have specific concerns regarding coverage for the test specimen, you should call your insurance provider ahead of your appointment to confirm that they will cover the laboratory cost of your test.

Result Interpretation

Positive / Reactive

A positive/reactive result suggests the presence of SARS-CoV-2 immunoglobulin (IgG), indicating an immune response to a COVID-19 earlier/previous SARS-CoV-2 infection or spike vaccine.

A minimum of 21-28 days after the onset of symptoms is suggested for IgG to be detected. Even though the correlation of IgG positivity and SARS-CoV-2 (COVID-19) immunity is yet to be settled, findings of IgG can indicate immune response after infection or vaccination.

As of now, the duration of IgG detectability remains unknown after exposure to SARS-CoV-2 or vaccination.

Negative/Non-reactive

A negative/non-reactive result suggests that the SARS-CoV-2 antibody is yet to reach detectable levels by the Antibody IgG test. Negative findings indicate that an individual has either never been infected with SARS-CoV-2, has been infected fairly recently (antibodies are still being/not yet made), or was infected too long ago. The individual remains at risk of infection, but the rate at which IgG develops ranges from person to person.

A measurable IgG antibody takes at least 10 days to be detected after vaccine or infection/exposure, but in some people, it may take up to 3 weeks or longer, and some patients do not produce antibodies at all.

Equivocal / Borderline

An equivocal/borderline result suggests that that IgG was observed at a concentration similar to the test’s limit of detection. Equivocal findings may occur for a variety of causes yet to be known, including an early infection, the identification of an IgG produced during a previous infection, or, in certain circumstances, an existing immune deficiency, immunosuppression, or other ailments.

Consider a repeat test after an additional 2-to-3-weeks.

FAQs

What type of test is the Antibody Test?

Antibody tests are done by collecting a blood sample, then submitting it to a laboratory for analysis. At this time, our SARS-CoV-2 antibody tests are laboratory-based, qualitative, and semiquantitative immunoassays; we do not offer rapid, point-of-care testing.

Can IgG antibody tests be useful to gauge immunity after vaccination?

At the moment, no. Under the FDA EUA, no antibody assays have an intended use/labeling for testing SARS-CoV-2 vaccine efficacy. Clinical experts are still looking as to what determines SARS-CoV-2 defensive immunity and longer vaccine effectiveness. It is still currently being researched.

Are antibody tests used to diagnose existing SARS-CoV-2 (COVID-19) infection?

No, antibody tests reveal whether an individual has built an immune response to a COVID-19 spike vaccine or has had a recent or previous SARS-CoV-2 infection. A PCR test can be used to validate the status of a current infection.

Does a positive antibody test result mean that one does not need a vaccine?

No, a positive test result holds no bearing on vaccines. Currently, the CDC and ACIP guidelines note that previous COVID-19 infection, whether symptomatic or asymptomatic, is not a safe alternative to vaccinations, and that serologic checking for SARS-CoV-2 antibodies is not advised prior to vaccination.

Does a positive antibody test mean that one has immunity?

Antibodies to SARS-CoV-2 mean that the patient has formed an immune response to the virus. The immune response may defend against reinfection, but this has yet to be shown concretely. It is unclear how long, if ever, antibodies to the virus will safeguard someone. Reinfection with COVID-19 has been confirmed, but it is still uncommon.

What level of antibody response in the Spike Protein test indicates immunity?

At this time, it is unclear what level of antibody response is needed for immunity to COVID-19. Clinical experts are still researching threshold levels that determine defensive immunity and longer vaccine effectiveness.