You Have COVID-19 Testing Questions. We Asked An Epidemiologist For Some Answers.

Is a car needed for drive-thru COVID-19 testing? Are self-administered tests accurate? What’s the difference between COVID-19 and antibody tests?

COVID Drive-thru testing
The Illinois National Guard operates a COVID-19 drive-thru test site for medical personnel and first responders at a closed vehicle emissions testing center in Chicago. Charles Rex Arbogast / AP
COVID Drive-thru testing
The Illinois National Guard operates a COVID-19 drive-thru test site for medical personnel and first responders at a closed vehicle emissions testing center in Chicago. Charles Rex Arbogast / AP

You Have COVID-19 Testing Questions. We Asked An Epidemiologist For Some Answers.

Is a car needed for drive-thru COVID-19 testing? Are self-administered tests accurate? What’s the difference between COVID-19 and antibody tests?

As COVID-19 cases surge around the U.S., and Chicagoans venture out more for work and play, the protocols for getting a coronavirus test seem ever changing.

WBEZ asked for your questions about COVID-19 testing. And now we have answers, with the help of Dr. Sadiya Khan, an assistant professor and cardiovascular epidemiologist at Northwestern University.

Below is an edited version of those questions and Khan’s answers, with names included from questioners who gave permission.

Question: Do you need a car for drive-thru testing? Can you walk up or bike up?

Answer: Some centers will let you walk up or bike up, and some won’t. Call ahead to find out.

Asked by Peter Contos, Albany Park.

Q: Why are the free sites run by the city of Chicago using self-swab saliva tests and not nasal or nasopharyngeal? Do the saliva ones have lower sensitivity?

A: It’s not clear why they’re picking that method, but it may be related to resources if they don’t have somebody to do the testing. The use of self-swab saliva tests is really for ease — allowing people to do their own tests and not expose the person testing them. (Note: A recent Yale study indicated that saliva tests may be better than nasal tests for accuracy, but the study is still awaiting peer-review.)

Asked by Sara Navin, Ukrainian Village.

Q: I’m worried that self-administered testing isn’t as accurate compared to if a professional takes a sample. Are there any discrepancies in test results?

A: It’s not clear yet, but we do know that getting an adequate sample is important to getting an accurate test result. As long as the average person is being coached appropriately, it should be the same.

Asked by Mariana Saucedo, Little Village.

Dr. Sadiya Khan
Dr. Sadiya Khan, an assistant professor and cardiovascular epidemiologist at Northwestern University. Courtesy of Northwestern University

Q: What are the fastest ways to get tested? Why haven’t so many people received results after weeks?

A: Call your primary care doctor or look on the Illinois Department of Public Health website to see which testing sites are open. Make an appointment, rather than walk in where you don’t know if the line could be hours long. Why are test results taking so long? It’s a matter of having the right resources to get the results, and so we are getting backlogged.

Q: Is testing really free in some places? I thought it was but you have to pay for an appointment before?

A: Testing centers are variable. Some are doing free testing, where they’re not taking any pay upfront. And some may be taking payment, but it should be covered by health insurance, so you should not be charged for the test.

Asked by Eileen Rohan, Evergreen Park.

Q: Can getting temporary unemployment benefits disqualify you from getting a test for free?

A: Temporary unemployment should not disqualify you from getting a free test.

Asked by Matt M., Uptown.

Q: What’s the difference between the COVID-19 and antibody tests? I have several family members not taking things seriously, because one of our relatives tested positive for the virus but later tested negative for the antibodies. Is this possible, or was one wrong?

A: The goal of the antibody test is to try to be able to assess if someone has been exposed to coronavirus. We know that as many as 25% of people who get the virus may have no symptoms at all, and that’s been a challenge in trying to be able to identify who has it and can transmit it as well. I think it’s too early to tell with the antibody test whether or not it’s accurate. One scenario is it was just a false negative result. So that person that was tested did have antibodies, and the test did not detect it.

The other possibility is that scientists are realizing that some people may not have mounted an antibody response or an adequate response to be detected by the test, but they did still have COVID-19.

And the third is that it’s possible that one of the other tests was wrong. Maybe they did not have COVID-19, and the antibody test is now showing no antibodies. That seems less likely, though.

Asked by Kelsey Kleidon, Oak Park.

Kristen Schorsch covers public health on WBEZ’s government and politics team. Follow @kschorsch.

Correction: An earlier version of this story misspelled the last name of question-asker Peter Contos.