Antibody Tests For Coronavirus: Not As Reassuring As We Need

My family medicine clinic this week has seen a big spike in patient requests about the new coronavirus antibody tests, probably due to all the press coverage of University of Washington’s lab starting their new test from Abbott. I share everyone’s interest in this test! I am with my colleagues and staff on the front lines fighting Covid-19, and all of us are very anxious to find out if we are already exposed. I would love to say that a positive test means we are protected and we can move on with life, while protecting our loved ones and colleagues. But at this moment, the current antibody tests do not offer the reassurance that you and I are looking for. So, at this time, I currently do not recommend people get the antibody screening test, here or anywhere else. I know it’s not what you want to hear, but allow me to explain.

There are many potential problems with the coronavirus antibody testing, as , the and many others have started to mention since last week. The main trouble with all antibody tests at this moment is that we don’t know what the results mean:

  • A positive antibody test is not an “immunity passport” to get back to work, as there is still no data whether people truly are protected. This includes all health care workers across the world.
  • We don’t know if having these antibodies give you immunity to the virus or prevents reinfection. Nor do we know how long it could protect you, whether for months like a cold or flu virus or for years like a measles virus. It’s very possible that it is protective, but we simply do not have that data. Many studies across the world are doing these studies, but results will take many months.
  • Just because you have antibodies doesn’t mean you’re not a carrier of the virus; you still could potentially be exposing others to infection.

Another major concern is that people who have a positive test for antibodies will be falsely reassured that they really are protected, and then they will relax their habits too much and thus potentially infect themselves or others.

I am also very concerned that the current antibody tests also may not be accurate enough, with too many false positives and false negatives:

  • A false positive would mean your test comes back positive but it’s actually an error, and you are not protected
  • A false negative means you actually have antibodies but the test comes back negative.

This issue became much more critical last week with the that the accuracy of 14 of these tests ranged from pretty good to essentially worthless. How many thousands of people are already walking around feeling falsely reassured?! The Abbott test at UW seems impressive, (true positives) and 100% sensitivity (true negatives). Here at Swedish, Labcorp is still assessing their new test’s stats. But even if you do get the most accurate test out there, you’re still stuck with all of those uncertainties I’ve mentioned.

My Test Was Negative

I am a bit embarrassed to tell you this after my spiel, but I have to confess that I got the UW antibody test last week. I, like all of you, was super excited and anxious to get the test, mostly because I was sure I had the infection back in February (a weird flu-like illness that felt different to me), so I really wanted to confirm that I already had it. My test came back negative, which surprised and actually disappointed me. I mostly was hoping that I was positive, which would make me assume that my family probably also had it and that we were all done.

But since my test last week, after reading all of these negative reports coming out, my result is much less impactful for me. My assumption that I would be “done” with the infection just aren’t accurate to say. (this is why we never assume…) I can’t even say with 100% certainty that the negative result means I didn’t have it, or that I don’t have it right now.

So I am back where I started, just like everyone else: full of uncertainty, a bit of fear, a dash of fatigue: add a pinch of frustration, stir and serve with a tall glass of red wine. But I am also feeling solidarity, a sense of shared struggle, a commitment to my job. Life goes on.

And I still cling to every evening that I return home not feeling sick. Since this all started, I feel a profound need to savor every moment and live in the present, which is a pretty healthy way to live anyway.


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One thought on “Antibody Tests For Coronavirus: Not As Reassuring As We Need”

  1. says:

Hi Richard,

While I agree with you that we cannot rely on an antibodies test, or any other tests, to be definitive at the individual patient level, I still think its very important that random sampling antibodies test studies are conducted in our community and country, because it will give us more data to guide our virus management approach. We have seen so much misinformation and outright wrong information, which has caused fear and panic, and we are now collectively paying a huge price for that.

Many, if not most, lay people believe that the goal is to completely stop the spread of the coronavirus, when in fact that is impossible without destroying the global economy, including our healthcare system.

Kind regards

Nis

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