Coronavirus antibody tests now available but concerns over reliability remain

Posted at 5:30 PM, Apr 29, 2020

Online shopping for a coronavirus antibody test didn't seem feasible just a few weeks ago. Now, with just a few clicks, this test can be yours.

But how reliable is the information the test provides?

The California Department of Public Health says a positive result from a coronavirus antibody test does not indicate protection from future COVID-19 infections and does not definitively indicate prior exposure to COVID-19. Despite this, many people on social media say they want the test.

Quest Diagnostic's website allows you to purchase a COVID-19 antibody test for $119, but you're not actually getting a box or swabs sent to your door.

Instead, you'll receive an "online consult with a physician who orders the test for you and sends the requisition (or prescription for the test) to a Quest location as well as the test itself," according to the company.

While these tests may put some people's minds at ease, healthcare professionals say the results might not be very reliable.

"They're not adequately accurate yet. There are false positives where a positive test is not really positive and there are false negatives. Those are significant issues," said Dr. Brian Roberts, Medical Director for MedStop Urgent Care Center. "[This is] true of almost every test we do, but we know more about other viruses so that we can predict when to worry and when not to worry."

According to the World Health Organization, as of April 24, no study has evaluated whether the COVID antibodies ensure immunity to the virus.

But Quest says their tests are 98-99 percent accurate, telling us in a statement:

The science on COVID-19 is evolving, and direct evidence that antibody testing may confer immune protection has yet to be established. In the case of SARS, which is in the same family of coronaviruses as COVID-19, previous viral outbreaks of SARS (SARS-COV), IGg [ or immunoglobulin g the body's most common antibody] has been shown to impute immunity for up to 2 years.

Dr. Roberts says it's still unclear the number of antibodies it would take to make someone immune to COVID-19.

"For example, with Hepatitis B, I know what antibodies you need and I know what level you need. When I test you, I don't get just a positive or negative, I get a degree of antibody of the specific antibody I'm looking for. We're nowhere near that with COVID-19," he explained.

So what can you expect if you still want the test? Quest Diagnostics says they draw blood from your arm and within one to two days, on average, you should get your results.