Coronavirus in Context: Maker of Diagnostic and Antibody Tests Explains How They Work

You're watching "Coronavirus in Context". I'm Dr. John Whyte, Chief Medical Officer at WebMD. We hear a lot about testing-- diagnostic testing, antibody testing. Well, today we're going to get some answers. My guest is Dr. Brian Caveney He's the Chief Medical officer and President of LabCorp Diagnostic. Dr. Cavaney, thanks for joining me.

So great to be with you, Dr. Whyte.

You've had some big announcements this week in terms of both, uh, at home test as well as antibody testing. Let's start with the FDA authorization of in-home coronavirus testing. Tell us how that's going to work.

Sure. That was a really big deal for us, and we're very pleased to be the first and only FDA authorized, uh, at home for self-collection. It's going to work--uh, right now we're doing it for symptomatic health care workers and first responders. It's a very simple process that we're all used to, like ordering anything else online, accessible from our website, pixel.labcorp.com.

You fill out a simple clinical survey and then enter a little bit more information. We'll send the kit directly to your home or apartment. You-- there are very simple, um, directions to follow to do the self-swabbing of a nasal swab, put it back into an insulated container, and then drop it off at your closest FedEx location that day so that it can be overnighted to us by FedEx directly to the laboratory that conducts the-- the analysis.

So you do the collection, and then you drop it off as well.

That's correct. And that, um, assures a very fast transport so that the specimen can stay in very good condition once it gets to our labs to be analyzed on our machines.

Do you have to meet criteria when you answer those questions? Or if you simply want one, you can get one? I know at first it's the, uh, you know, uh, first line responders and physicians. But ultimately, um, is that what you see?

We--we expect over time, as we're able to build more capacity for the kit itself, to expand to other populations. But we really did want to focus on this really high priority, uh, population, both from the CDC, the White House Task Force. And as we all know, symptomatic health care workers and first responders on the front line, we need them back in the game when they're ready to go, and we need them on the sidelines if they potentially have COVID-19, so that they can protect the vulnerable populations they serve.

How soon do they get test results back?

Once we get the specimen into our lab, it's just a matter of hours for us to process it through the same clinical workflow that we process any of our other PCR specimens coming from hospitals or doctor's offices. And then we have it set up on the machines as a panic value, meaning if we detect the virus, it immediately alerts the bench scientist to contact first the public health authorities under the communicable disease reporting laws, then the ordering clinician, and then we make the results immediately available to the patient who ordered the test in our patient portal.

Let's talk about accuracy because a lot of folks have been talking about in general, are tests for coronavirus accurate enough? There's a lot of math involved. We don't have to go into, you know, positive predictive value and negative predictive value and all of that. But can you help educate folks in terms of the accuracy of this test? And the standard for authorization does require that you be as accurate as a test done, uh, by health professionals or in a doctor's office.

BRIAN CAVENEY: That--that's exactly right. There are three important components of the overall process. And we spent several weeks working with the scientists at the FDA literally every day to make sure that they were comfortable with and validated every step of the process. And we submitted all of that data that's available on the FDA website in our emergency use authorization forms.

Uh, once we get the specimen into the lab, as you mentioned, it's run on the same exact equipment as any other specimen coming from health care facilities. And so that is the top of the line, best in class machinery. We are very, very good at identifying and detecting the virus if it's in the specimen we get.

The process right before that, of course, the transportation. We want to get it as fast as possible from your house to our lab to maintain the integrity of the specimen, make sure the viral coat is still intact, and it's more likely that we can identify the virus in there. That's why we have FedEx overnight it directly to our laboratory.

The process that is probably most important in making sure there's a good outcome is the very first part, and that is the quality of the specimen that you can get. It-- the swab itself looks a lot like a-- a Q tip cotton swab, if you will. And we have the person go into both nostrils and swirl it around two or three times in order to get some of the epithelial cells which contain the virus if the person is shedding virus.

And the nice part is, because we're starting with health care workers and first responders, who better to be able to get a good specimen and to do that really well on the front end--

We hope. So that we can a lot of data and validate that process.

We hope they can do it well, but you never know. We'll-- we'll be optimistic.

That's right.

And this is a--a desire to really help build capacity. We've been talking about having to do, uh, more tests. We get a better sense. That-- that's terrific.

I want to move on to antibody testing because we've been having a lot of discussion about the accuracy of the test, the availability of tests, what do they actually tell patients, what's the difference between point of care testing and then more of a quantitative analysis. Um, so you also have an antibody test for coronavirus.

And let's start off with who's that for? You're pretty clear, in terms of the description, who that test is for and who it isn't. So can you help, uh, talk to our audience about that distinction?

Absolutely. You're--you're right. There are multiple different types of tests, it is a little bit complicated, and we're working with some of the best scientists in the world to sort out all of those different use cases. We've had many conversations with the doctors at our, uh, hospitals we work with and large clinics to really understand how they're going to use it and what clinical questions they're going to answer by adding this to their toolbox of other things that they might do to-- to diagnose and treat their patients appropriately.

Some doctors are going to use it as part of the overall clinical picture if they're not sure if someone has COVID-19 versus another respiratory disease versus another type of a condition. Some of the different antibodies show up earlier in the course of the infection, some show up later. And some doctors are going to use it for that particular purpose.

But really, uh, different than what most people are used to when they go to the doctor, are other uses of the serology test, all over the media this week with big surveys in New York and California and other places. And those tend to be population surveys or surveillance studies.

And we're participating with the CDC and with many academic medical centers to do that, where basically, if you get those tests on a large number of the population, you can directionally have a good sense of how many people have been exposed to the--the COVID-19 virus, how many of those were asymptomatic and didn't know it. And you can do other planning measures around policies such as when can we reopen the economy?

We're also using it, uh, in other ways with certain customers that want to think about when is it safe, for example, for emergency room nurses or ICU nurses to go back to work after they have been exposed, uh, or if-- if they're not sure they have been exposed.

None of the science is perfect yet on it. There are some really good research studies underway to understand what exactly these antibodies mean, when they show up, and what conclusions we can make from it. But it's going to be important going forward.

There are other uses for them as well, including whether or not a person is, um-- has a strong immune response to the COVID-19 virus and would be a good blood donor for the plasma therapies that are being used. And we're also using it with a variety of, uh, drug companies and medical device companies in clinical trials, so for example, with vaccines and other medications that are being developed right now to treat or prevent VOCID-19.

Correct me if I'm wrong, but for most people this test for antibodies is not if you think you currently have the disease with symptoms. But for most people, it's going to be that you think you might have been infected. Is that correct?

That is a really important point, John. Yes. The serology tests or the antibody tests are not used to diagnose someone with COVID-19. In fact, that's directly in both the labels and in the reports that we will have available for doctors who order this for their patients.

To diagnose it, you have to use the-- the PCR test or the swab test that I mentioned earlier. The blood-based serology test purely means that your immune system has seen the virus before and your immune system is mounting a response to it by developing those antibodies after the fact.

So Dr. Cavaney, what we're talking about here is not a point of care test, is that right, where you do a pinprick and you typically get a qualitative report, which means you have antibodies or you don't. This is one where you're going to go into the lab and have a blood drawn, and it's going to give you different types of information. Can--can you walk us through that? And please correct me if I'm wrong.

That's an important distinction. Right now it appears that the higher quality test is to have a venipuncture, which means you get your blood drawn from your arm. And then that is sent into the laboratory to be analyzed on one of the chemistry machines that looks for the antibodies.

In the future there are likely to be some point of care devices. A way to think about it, maybe, for most people, is you may have been to your doctor's office or an urgent care and had a rapid flu test that was done there using a-- just a small cartridge that you've seen on the countertop. But often, they will take swabs and then send it back into the laboratory, or take blood and send it to the laboratory to confirm what the point of care device showed.

And this test is looking at the different types of antibodies, is that right, including neutralizing antibodies, where there's a lot of interest.

Right now there are tests on the market for three of the main antibodies that doctors like to look for called A, G, and M. Neutralizing antibodies is something a little bit more, um, sophisticated, where the antibody very directly is known to kill the virus or neutralize the virus. Those will eventually be on the market, but for right now, those are only used in research trials and not generally available on the market.

Can you talk a little bit about how confident you are that the presence of antibodies is going to give protection, because that's really what we're trying to sort out. And there's some good data pointing to that, but--but I wanted to get your thoughts.

That's a really important point. For right now, we don't have incredible confidence in two things. If you have the antibodies, does it mean that you, the patient with the antibodies, cannot get infected with the COVID-19 virus again? We don't know that for sure, but it's likely.

But really importantly, if you're thinking about, for example, a health care worker who's using it to determine if she can safely go back into a part of the hospital that has a lot of COVID-19 patients, or--or people who don't have COVID-19, if she has the antibodies, does it mean that she no longer has the virus and can't transmit it to anyone else?

Most doctors think, because of what they know from other conditions, that's likely to eventually be the case. But we can't say that definitively right now until we do a lot more research and really understand the time frame and-- and what percent of the population that develops.

Now how does one get this test? They need a prescription by a doctor?

In almost every state in the country, you do need a prescription from a doctor or another health care professional in order to get any lab test. Because it's a blood-based test with a blood draw, you can get it at your doctor's office, at urgent cares, at many of the patient's service centers that national laboratories like LabCorp have spotted all around the country to make it more convenient.

But you need that order. You just can't show up yourself and get it, is that correct?

That is correct for now, yes.

Can you tell us what else you're working on?

We're very excited to be working across the board with various vaccine and medication clinical trials. We've developed our own data registry on all of the COVID-19 patients that we've been able to detect over the past couple of months or so, so that we can help do more research on what exactly causes someone to get the disease more severely than others? And what is it about someone who had it and was completely asymptomatic?

We can look at many of the other lab tests and biomarkers that we may have already done for other reasons on those patients and try to learn more so that we can help the situation.

And if viewers are interested in learning more about these tests-- the diagnostic test, antibody test-- they can talk to their doctor. But where else can they go?

Obviously, WebMD is an amazing resource.

Thank you, thank you.

And hopefully they're looking there. We try to have a lot of information geared for different audiences, including the public, as well as health care professionals, on our website, which is just labcorp.com.

Well, Dr. Cavaney, I want to thank you for taking the time to talk this afternoon.

My pleasure, Dr. Whyte. Thank you for educating the public on this really important concern.

And thank you for watching "Coronavirus in Context".