Coronavirus tests for antibodies coming, but public health experts question accuracy

ByChuck Goudie and Barb Markoff, Christine Tressel and Ross Weidner WLS logo
Thursday, April 16, 2020
Coronavirus antibody tests are coming, but experts question accuracy
A new kind of coronavirus test is on the way but public health experts are warning about its accuracy and what could be a false sense of security.

CHICAGO (WLS) -- Many Americans are hopeful a simple blood screening to check if they have antibodies to COVID-19 could help get them back to work, school and a more normal existence.

There are dozens of tests on the market offering to provide that information, but an I-Team investigation found there are growing concerns about the regulation and accuracy of many tests.

"There's a lot of confusion going on in the medical field right now on the serological testing," said Dr. Rahul Khare an Emergency Medicine Physician and CEO of Innovative Express Care in Chicago's Lincoln Park neighborhood.

Khare has been testing patients for the COVID19 virus in tents just outside his clinic, to tell if they are currently infected.

He wants to start offering a serological test, also called an antibody test, to determine if someone has already been exposed to the virus. But he's running into the same dilemma as other healthcare professionals.

"It's really difficult to tell which tests are more reliable than the others, the ones that are FDA approved or have an EUA emergency use attached to it are the ones that health care workers should really be using," he said.

Last month the FDA loosened its standards in an attempt to help make more tests quickly available.

According to U.S. regulators, many dozens of serological tests for COVID-19 are now on the market

But some public health officials, infectious disease experts and laboratory owners have been sounding the alarm about the lax oversight.

They said the tests need to meet standards and prove that they actually work

In response to the growing outcry the U.S. Food and Drug Administration announced government scientists will begin reviewing data on some of the antibody tests to see if they actually work.

READ MORE: USDA FAQs on Diagnostic Testing for SARS-CoV-2

Scott Becker, the CEO of The Association of Public Health Laboratories considers that a good first step.

"We are hopeful the evaluation will be completed very soon and that that data is going out be made available so that we can get a sense of the quality of these tests," he said.

The FDA's commissioner said in a statement the agency will take action against any company making false claims about antibody tests or selling inaccurate tests.

Serological tests are blood exams that look for antibodies - human infection fighters - and antibodies can indicate if you've had the virus and might now be immune.

In theory you would not get infected again and you wouldn't be a risk to others.

But just because someone has antibodies doesn't necessarily mean they are immune.

North Shore University Health System was the first Chicago area hospital to perform its own in-house coronavirus testing for patients.

Dr. Karen Kaul, the Chairman of the Department of Pathology, said she is helping vet the anti-body tests.

"And we're seeing this in the, in the laboratory now that there are variable degrees of performance of these tests," she said. "And they're making claims about performance that are not being borne out by our experiences either. "

Kaul is optimistic about the serological testing and said research will eventually help determine which ones are most reliable. But she also cautioned the public not to get too excited about the antibody measure because it may not be a sure guarantee against reinfection.

"So, at this point I think having a positive antibody test is a value that you likely did have COVID-19 or a past coronavirus infection, but I think it's too early to say that this means you're immune to future infection," Kaul said.

The test results may be most useful in revealing how the virus spread throughout the U.S. population.

For an anxious public it might provide a sense of relief and it could help officials decide when to lift the stay-at-home order.

Currently there are not tests approved for at home use. Dr. Khare encourages anyone interested in taking the test to do so through a healthcare provider.

"It's really, really important to have a physician who can understand the results and kind of tell you what, what they mean," she said.