While tests to determine if you’re actively infected with the novel coronavirus have been available (albeit in limited quantities) since March, so far, we haven’t been able to uncover if a person has already had COVID-19—until now. As of Friday, April 24, National Jewish Health is testing Coloradans for coronavirus antibodies. We spoke with Jay Finigan, a pulmonologist at National Jewish Health and director of the Respiratory Centers of Excellence, to find out more about the test, its accuracy, and whether or not a positive result indicates immunity.

What is the antibody test?

Antibody tests, also known as serology tests, check for antibodies in the blood that might have been generated in response to a virus. When a patient becomes infected with SARS-CoV-2, the virus that causes COVID-19, their immune system generates COVID-19-specific antibodies to fight off the infection. National Jewish Health’s antibody test checks for these antibodies in order to determine if an individual has had COVID-19 in the recent past—which is extra important since many people who are infected with the virus are asymptomatic.

“If you have those antibodies, it’s a sign that you were infected anywhere from days to months in the past,” says Finigan. Currently, this test cannot definitively point out when a person was infected, only that they had the virus at one point.

How reliable is the test?

As with any test, there is a margin of error. “No test is 100 percent specific, and only recognizes the one thing you want it to recognize. Every test has an element of cross-reactivity. The data we have now shows that our test has very low cross-reactivity,” says Finigan.

National Jewish researchers are still determining the exact margin of error for their test; however, they conducted extensive testing between different antibody tests to determine which was the most effective. The test that is available today was deemed the most accurate.

How many tests are available?

The number of tests available each day may vary significantly depending on supply. Antibody testing will likely experience the same supply-chain issues that hospitals have been experiencing for months and have hindered the U.S. response to COVID-19 from the beginning (availability of masks, ventilators, tests, and swabs). “Issues with the antibody tests are the same,” Finigan says.

For the first few days of testing, National Jewish is aiming to complete between 100 and 200 tests a day. This number is partially to ensure the new testing does not overwhelm the system. “At the same time, we are actively trying to build capacity,” Finigan says. “It wouldn’t surprise me if in a week to two weeks we’re doing more [tests] than we’re doing now.”

Should I get the test?

If you’re currently experiencing COVID-19 symptoms (cough, fever, shortness of breath, etc.), this is not the right test for you. Instead, you should get the molecular diagnostic test (in the form of a nasal swab), which tests for the virus itself. You can get this test through a doctor’s referral.

If you do not currently have COVID-19 symptoms and suspect or want to know if you might have been infected with the virus in the past, this test is for you. While National Jewish Health is currently in the process of creating a triage list, testing is currently encouraged for anyone who wants to get tested.

Widespread antibody testing is beneficial for various reasons. It’s an essential part of determining the extent of the COVID-19 epidemic and can be used to guide government decisions for when and how to restore economic and social activity. “Once more of these kinds of tests are done, we’ll have a better sense of how many people have been exposed that didn’t even know it,” Finigan says.

Researchers are also in the process of developing and implementing a system of using the plasma of those who have COVID-19 antibodies for therapy in people who are acutely infected. If these treatments ramp up, certain people—such as those who experienced symptoms or were confirmed to be infected—may be prioritized over others for antibody testing.

What if I’m immunocompromised?

Technically, someone who was infected with COVID-19 can receive a negative antibody test result. The amount of antibodies produced in response to a virus depends on the person. If you are immunocompromised, you may not produce enough antibodies for detection.

However, this does not necessarily mean you shouldn’t have the test. “If somebody has been able to produce antibodies to vaccines in the past, there’s no reason to think you wouldn’t be able to do that to a current SARS-CoV-2 infection,” Finigan says. Yet, if you are immunocompromised, he recommends following the guidance of your physician to decide whether or not to get the antibody test.

How can I get the test?

There are two ways: First, you can sign up for the test online without a physician referral (however, due to high demand, all available timeslots are currently full). If you go this route, you will choose a drive-through testing appointment for either the same day or within the next few days. When you arrive for your test, workers will draw your blood and send the sample to a lab (then all you need to do is wait 24 to 48 hours for the results). Second, you could get the test through your physician, using this form. The National Jewish Health scheduling team will be in touch to find a two-hour window of availability to schedule the drive-through test. You show up for the test and your physician will receive your results in 24 to 48 hours and get in touch with you.

How much is it?

Each test costs $94.

Will my insurance cover it?

It depends. If your doctor orders the test, it can be billed through insurance. If you do it on your own, you will pay for it out of pocket.

If my antibody test comes back positive, does that mean I am immune?

Experts don’t currently know if getting COVID-19 once makes it less likely or impossible that you will get it again. “We suspect that might be the case, but we don’t definitively know that yet,” Finigan says.

National Jewish Health researchers—and researchers around the world—are actively testing the extent of immunity to COVID-19. National Jewish Health researchers do not anticipate discovering this information for another few weeks or months, though exactly when this information will be available is hard to predict.

If I’m confirmed to have had COVID-19, should I change my behavior at all?

No. Knowing that you have been infected with the SARS-CoV-2 virus and recovered does not exclude you from the social regulations that keep everyone safe. “This doesn’t replace hand washing, social distancing, you know, the common-sense measures we’ve all been putting in place,” Finigan says. “Those are still sort of the foundation of how we’re going to manage this pandemic right now.”