• A positive COVID-19 antibody test means you’ve had the infection in the past and suggests you’re immune to it.
  • A pin prick antibody test using a drop or two of blood is likely to be less accurate than a test done using blood taken from a vein.
  • COVID-19 antibody testing needs to be very specific and mass testing should be delayed until research validates its accuracy.
  • The availablity of a COVID-19 vaccine is still at least 18-20 months away.

Video Transcript

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JOHN WHYTE: You're watching Coronavirus in Context. I'm Dr. John Whyte, Chief Medical Officer at WebMD.

Coronavirus can be scary. There is a lot we don't know. Should you get tested? What's the role of antibodies? What treatments actually work? When will a vaccine come? And how long do we need to stay in place?

Despite all of this uncertainty, there are some things that we do know, and we need to rely on sense. That's what's missing from much of the discussions, a common sense approach to dealing with coronavirus. That's why I think you'll want to listen to my next guest, Dr. Michael Saag from the University of Alabama at Birmingham. He offers the common sense insight that we need to make good decisions. Dr. Saag, thanks for joining me.

MICHAEL SAAG: Thanks for having me.

JOHN WHYTE: Let's start off with who should get antibody testing.

MICHAEL SAAG: Well, ideally, the-- the prime people are people who feel like they've been exposed to, uh, COVID-19 and did not have symptoms, and they're suspicious that they may have been infected but have not had any symptoms at all, are asymptomatic. And that-- if the test is working well-- and that's a big if-- um, then that would tell them that they had the infection and may be protected by, uh, immunity.

JOHN WHYTE: Do you think the presence of antibodies to COVID-19 do grant immunity? There's been a lot of debate whether or not that's the case. What do you think?

MICHAEL SAAG: Well, let's start with I hope it does, for a lot of reasons. First [INAUDIBLE]--

JOHN WHYTE: We all hope-- we all hope it does.

MICHAEL SAAG: Right. I've had COVID, and my antibodies are through the roof. Um, in fact tomorrow I'm donating plasmapheresis so that it can be used in research. But the take-home point is we don't know for sure. And I can argue with equipoise that it would from other viral infections, um, when we think of measles, mumps, that type of thing, and then we look at the other extreme with dengue fever, which you get antibodies, but you get not only re-infected, but your disease can be worse on the re-infection. So somewhere in that spectrum, this will fall. But my personal stance is so far that we're really not seeing any cases to speak of where somebody had it and then got sick again. So my-- I think as more time goes on, we'll answer the question, but right now, we don't know for sure.

JOHN WHYTE: Do you think there's more evidence than not that it does give some degree of protection?

MICHAEL SAAG: Leaning that way.

JOHN WHYTE: OK.

MICHAEL SAAG: But I don't-- we can't say more now.

JOHN WHYTE: Now, what about these re-infections that have been reported? Most people are saying those are issues of testing, and not of re-infection. It's a simple RNA virus, it's not like zoster. What-- what are your thoughts on that?

MICHAEL SAAG: Well, the-- if we dig into the weeds a little bit on those stories, what it was mostly was somebody who tested positive for virus, then tested negative and tested positive again. The question is--

JOHN WHYTE: [INAUDIBLE] symptoms, correct, yeah.

MICHAEL SAAG: But without symptoms, right?

JOHN WHYTE: On the retest?

MICHAEL SAAG: On the retest, they have been sick--

JOHN WHYTE: Mhm.

MICHAEL SAAG: --they had virus, they got better, they tested negative, and then they tested positive again later, is my understanding.

JOHN WHYTE: OK. Why were they retested, then?

MICHAEL SAAG: I think they were looking to see if there was persistence.

JOHN WHYTE: OK.

MICHAEL SAAG: And so the-- the issue is was it truly a re-infection or was it just persistent RNA that they picked up a second time later on. And I don't know the answer, but my feeling is that they probably weren't. The way to really know for sure is to do molecular virology, where you do sequencing and see if it's related. But right now, I think the common sense is telling me that people are probably not getting re-infected, and that any residual testing that's positive-- and some-- I've seen it going out to almost five weeks-- um, is just residual RNA. And the question is, is that an infectious [INAUDIBLE] that's being picked up, or just a remnant? And so far, the culture tests show that, by day 14 after onset of symptoms, there's-- you can't culture virus anymore. So I think it's probably remnant.

JOHN WHYTE: And some of it may relate to the timing of testing, correct? We don't always hear when exactly they were tested.

MICHAEL SAAG: That's exactly right.

JOHN WHYTE: And I appreciate your common sense approach. You say we need some common sense. So I want you to make sense, if you can, of what we're hearing about the number of antibody tests that are out there. And-- and I'll tell you, I've worked at FDA, so I know an authorization, it's a term in the weeds of regulation, but it's a lower level of standard. They don't even actually have to, um, get all of their data, uh, completely done prior to coming on the market. We're in a public health emergency. We want to get things out there. But that's caused challenges with the accuracy of the tests. How concerned are you about the accuracy, and hi-- how would I, as a patient, if I wanted to go get one, how would I know I'm getting a-- a good one?

MICHAEL SAAG: Start at the end and say you aren't going to know. And that's a huge problem. And I get it. I understand why the FDA relaxed and went to early authorization, to use that technical term. But I think in retrospect, it was probably a disservice to us, from a common sense perspective. Here's why. We all have been infected with a coronavirus in our lifetime, with common cold. Not every common cold, but a lot of common colds. So that means that we have antibodies to coronavirus in our bloodstreams that are just hanging around. If the test for the SARS-CoV-2, the COVID-19 virus, for antibodies to that is not really specific for that particular virus, there will be cross-reaction from these other coronavirus antibodies onto that test.

So somebody could get a positive read for an antibody to coronavirus and assume that it's because of SARS-CoV-2 and feel like, well, maybe I'm protected, I can relax. And that's a disservice. So a tip of the hat to the FDA for what they do every day that we take for granted, right? They-- they insist on rigor before they approve things. And by relaxing those standards into this, I understand that-- why they did it, but I think they've done us a little bit of a disservice from a common sense perspective.

JOHN WHYTE: Does it matter if I get a pin prick or I go to a lab and have my blood drawn? Is the blood draw a--

MICHAEL SAAG: Ab--

JOHN WHYTE: --better test, or?

MICHAEL SAAG: --absolutely. Absolutely. Because-- because-- yeah.

JOHN WHYTE: Why is it better?

MICHAEL SAAG: Well, because with a blood draw, you're getting-- you're getting plasma. You're getting actually a large volume that can be run on a test. The pin prick, you're getting just a drop or two of blood, and it's less likely to be accurate. So I think that, for right now, what we need are standardized tests with published false positive rates.

And right now, even if-- I'm going to go into a little statistics here, but if we have a test that's got, say, a-- a 3% false positive rate, which 97% specificity, right, if we apply that to a population that has less than 5% prevalence, so the majority of people haven't had it, that test in terms of what we call positive predictive value could be wrong 50% of the time. That's not helpful.

JOHN WHYTE: So it depends on the number of people who have a disease in the population.

MICHAEL SAAG: Exactly. And I'm sorry to bring everybody back--

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--the point is that the test, for this to really work well in a disease that is only affecting, at most, 2% to 3% of the population at most, we need a test that's at least 99.7% specific. And I'm not sure we have that proven yet. So I would hold tight, is the take-home point, on getting antibody tests until we have a lot of validation.

JOHN WHYTE: You were infected with COVID-19. You graciously agreed to share your story. And we're going to hear about what you did about testing. Um, tell us how you got infected with COVID-19 and what's been your experience.

MICHAEL SAAG: So it was an accident of sorts. My son, who lives in New York, was coming back to Birmingham. He was going to drive. And so I was in Boston. I took the train, met him. En route, he started not feeling well. And by that day we got to Birmingham, he was having fever. We looked at each other. We knew that he almost certainly had COVID. We quarantined ourselves in the house. I got sick the next day. Not terribly bad, but by day five and six, it was pretty awful. And as a physician, as a provider, the worst thing was knowing what would happen if my breathing deteriorated. I would be in the hospital, possibly on a ventilator. And that was a nightmare scenario for me. So every night for eight nights in a row, I suffered through that anxiety of worrying about it. Fortunately, by day 14, it went away.

JOHN WHYTE: Did you and your son get a test?

MICHAEL SAAG: Yes. We were tested virologically on day three of my illness, when we both tested positive for the virus. So we definitely had it. And afterwards, we actually--

JOHN WHYTE: [INAUDIBLE] well, so that's a success story, as most are success stories.

MICHAEL SAAG: Yeah, they are.

[INTERPOSING VOICES]

JOHN WHYTE: OK.

MICHAEL SAAG: So but we volunteered for a research study looking at immune response on the day we got tested for the virus. And that study has continued, which segues to the antibody because we sent the blood off to colleagues of mine, uh, at University of Pennsylvania, who have made a very specific test for research purposes. And I have a-- about a titer of 30,000, which is really high. So tomorrow, I'm being plasmapheresed so they can use it a lot of, uh, test validation.

JOHN WHYTE: What about the role of convalescent plasma? Um, is there value there in-- in treatment of critically ill patients? Is that something that you're considering?

MICHAEL SAAG: Well, yes. And it seems like in early reports that it is helpful in some patients. So, uh, my son donated for plasma donation and gave it. Uh, and I don't know how many patients it was given to in New York. Uh, I elected, because of the titer, to first donate for research, and then, if needed, I'll donate for, uh, patient plasma, as well.

JOHN WHYTE: In our last minute, you-- you've mentioned common sense throughout this. And-- and I love that, um, description. What common sense advice do you have for viewers that are concerned about coronavirus? We're several weeks into the epidemic. Most people think we've reached our peak and on the downward trend, though still a serious condition. What common sense advice do you have for folks?

MICHAEL SAAG: Common sense is that the virus, all it cares about is survival and replication. And it's still here. We have the vast majority of citizens in our country who are susceptible. We've been successful at putting a wall between them by these stay-at-home orders. You take the wall away, what does common sense tell you? These things will come back together, and we're going to get another surge in cases. So we have to be smart and be able to keep patients away from the virus, keep susceptible people. And that can involve a series of measures, but the fact that this thing-- excuse me-- this thing is here, it's not going away anytime soon. And I think we all need to start getting that into our head, not just awareness, but to the point of comprehension. What does it mean to be living with this virus in our midst for the next several months? It's going to take sacrifice.

JOHN WHYTE: Is a vaccine going to be here in 6 to 12 months?

MICHAEL SAAG: No. We'll have-- even if we had one that we knew worked, you're going-- we're going to have to mass produce it. If there's 300 million people who will need the vaccine in the US, that's-- if you assume two doses-- 600 million doses, and then that's a worldwide pandemic. We aren't going to be able to, even if we had a vaccine, scale up to that degree of production for at least 18 to 20 months.

What's the optimism? Hopefully, some of the drugs that are in development are shown to work. And that would be a game-changer because, even if someone got infected, we catch them early like we do with oseltamivir, tamiflu, with influenza, if you catch it early, you intervene, you ab-- you abort the symptoms, and then the person still will develop immunity, but they won't get as sick. That's the hope.

JOHN WHYTE: Well, Dr. Saag, I want to thank you for sharing your insights.

MICHAEL SAAG: Thank you for having me.

JOHN WHYTE: And I want to thank you for watching Coronavirus in Context. I'm Dr. John Whyte.