The Future Of Immune Health Might Be Here

David Ewing Duncan http://www.davidewingduncan.com/ has spent the last 25 years being poked and prodded in the name of science. He’s signed up for hundreds of tests because, as a journalist, he writes about emerging health breakthroughs. He says one recent test contains more useful data than anything he’s seen to date. He talks to host Emily Kwong https://www.npr.org/people/767284140/emily-kwong about his score on the Immune Health Metric, which was developed by immunologist John Tsang https://medicine.yale.edu/profile/john-tsang/. Together, David and John explain why immune health is so central to overall health and how a simple blood test could one day predict disease before it starts. Learn more https://www.humanimmunomeproject.org/ about the Human Immunome Project. Read https://www.technologyreview.com/2025/10/09/1125376/how-healthy-am-i-my-immunome-knows-the-score/ David’s full article about his experience with the Immune Health Metric. The piece is a collaboration between MIT Technology Review and Aventine, a non-profit research foundation that creates and supports content about how technology and science are changing the way we live. Read the story on Aventine's website here https://www.aventine.org/technology/human-immunome-immune-system-test-john-tsang. Interested in more health science? Email us your question at [email protected] mailto:[email protected]. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave http://plus.npr.org/shortwave. See pcm.adswizz.com https://pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences. NPR Privacy Policy https://www.npr.org/about-npr/179878450/privacy-policy

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• 0:00Speaker 00

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• 0:18Emily Kwong?

  You're listening to Short Wave from NPR.

• 0:23Emily Kwong?

  David Ewing Duncan describes himself as the experimental man.

• 0:29Speaker 02

  25 years ago, I was one of the first humans to have my DNA sequenced for a story for Wired magazine.

• 0:35Emily Kwong?

  David is a journalist and a science writer.

• 0:38Speaker 02

  And we almost didn't do the story. It seemed a bit gimmicky, but we did it and it really resonated with people. And so I was kind of off and running.

• 0:46Emily Kwong?

  And he has made a career out of this, out of signing up for tests promising new insights into health and mortality. After sequencing his genome, he later tested his proteome, the proteins circulating in his blood, then his microbiome, then his metabolome.

• 1:01Speaker 02

  And I've got about, I don't know, at last count, about 70 terabytes of data of myself, which is an extraordinary amount of data. A lot of that is, I got a lot of MRI scans, so that eats up a lot of bytes.

• 1:13Emily Kwong?

  It is really a twist on the line in Hamlet, "know thyself."

• 1:17Speaker 02

  Yes.

• 1:18Emily Kwong?

  But in all these terabytes of data.

• 1:20Speaker 02

  Maybe 98% was not useful.

• 1:24Speaker 02

  But the 2% this man, John Tsang, is largely responsible for.

• 1:28Emily Kwong?

  John Tsang is a professor of immunology at Yale University, and he and his colleagues have devised a test to measure immune health. They call it the immune health metric. And when David, the experimental man, heard about it, he said, "Sign me up."

• 1:44Speaker 02

  I've had long haul COVID twice. I've had a couple of surgeries. Like, what is my immune system health?

• 1:50Emily Kwong?

  Otherwise known as the immunome, made up of many genes and proteins.

• 1:55Speaker 02

  It's probably the most important system in our bodies. It literally decides if we're going to be able to heal ourselves when we get an infection or a disease. It's health, our lack of health is.

• 2:09Speaker 02

  You know, different than our actual biological age.

• 2:12Emily Kwong?

  And as John reminded me, there's roughly 1.8 trillion of these little immune cells hanging out in your body right now, seeing what's good.

• 2:20Speaker 03

  And many of them are residing in different organs and tissues. Many of them also move around your entire body. They patrol and they try to check, check out different tissues and organs and then they see what's going on.

• 2:33Emily Kwong?

  To respond by, say, running up your body temperature to fight a cold, return your system to homeostasis, and to remember those threats for next time.

• 2:43Speaker 03

  Has to remember, have I seen the flu? Have I seen the COVID? Or have I seen a lot of inflammatory signals? So now in my next response, I may want to anticipate what's coming in.

• 2:53Emily Kwong?

  John's test, the immune health metric, requires a blood sample. So David gave us blood and after a ton of fancy calculations, got his score, this snapshot of his immune health. He was nervous about how he'd fare. And then he got the text from John.

• 3:08Speaker 02

  So my score was 0.35.

• 3:11Emily Kwong?

  And how did you feel about that?

• 3:13Speaker 02

  I honestly didn't know what to make of it. You know, it's just a random number. And I had to get a lot of explanation before I really understood what that score meant.

• 3:23Emily Kwong?

  Today on the show, the future of immune health may be here now. Can extremely personalized medicine unlock the secrets of how healthy you are and how long you may live? Plus, what David's score means. I'm Emily Kwong. You're listening to Shorewave, the science podcast from NPR.

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• 5:09Emily Kwong?

  All right, John and David. I want to start by talking about how doctors have historically assessed people's immune health in the past. Like, how is immune health measured, John?

• 5:19Speaker 03

  They actually don't have a very good way to summarize overall how's your immune health. All we got typically, if your doctor orders it, it's what's called a CBC. It's a complete blood cell count.

• 5:33Emily Kwong?

  Complete blood cell count. I know the CBC is the Canadian Broadcasting Corporation.

• 5:37Speaker 03

  That's right. I'm Canadian.

• 5:38Emily Kwong?

  Oh, nice, nice.

• 5:39Speaker 03

  So the complete blood count, it provides you with the absolute count and frequency of certain cells in your blood. That's nothing very specific. You can basically tell by just looking at those numbers. But how to link the CBC to the healthy immune system and how to link the CBC to other aspects of your health, it's still an open problem.

• 5:59Emily Kwong?

  David, why is that test, the just simply counting, not enough?

• 6:02Speaker 02

  Well, the CBC just tells you there's something going on in your body. I mean, your body is incredibly complicated. And, you know, there's some infection somewhere. So it doesn't tell you where it is. It doesn't tell you what it is.

• 6:14Emily Kwong?

  And so the complete blood count, the CBC, that has been the standard, more or less, for assessing people's immune health for decades. But now, John, your lab has developed a new test, the immune health metric. How did you make this test?

• 6:29Speaker 03

  In our case, we started with both clinically healthy people, so no obvious disease, and then also various groups of people suffering from various genetic defects. Each one of these persons is like suffering from a natural perturbation, or it's like a hammer knocking stuff around, right, in their system. If we look at enough of these peoples, where the hammer is knocking on different points in the immune system, we can build a map on how different parts of the immune system, it's connected to each other, number one, right? And number two, we can start to ask the question, despite that these diseases originated from different parts of the immune system being perturbed,

• 7:13Speaker 03

  are there common deviations? And we call that common deviation from health.

• 7:17Emily Kwong?

  It's like knowing the immune system on a far deeper holistic level than merely like it exists.

• 7:24Speaker 03

  Correct.

• 7:24Speaker 02

  Yeah, right now, medicine is still practiced organ by organ, system by system. And we've been tending towards this idea that actually, we do have a system that's connected together. And we now really have, through John's work and others, a way to show how the body really is working as a holistic unit. And the immune system is key to that.

• 7:45Emily Kwong?

  John, you also used AI to develop the test? How so?

• 7:49Speaker 03

  Where the AI came in is very intriguing. It's we thought, well, now let's represent each person just as a string, long string of numbers. You now have a map that you can place each person on that map, right? If you take the very first dimension, that explains the most amounts of differences across all of these people that we have looked at, correlated almost perfectly with this probability of someone being healthy. It's AI was rediscovering, in a way, our probability of being healthy axis. And that's super intriguing because it suggests that that's the most fundamental wavelength, in a way, in the system. And then, once the AI is done, we can go back and ask, what?

• 8:34Speaker 03

  Did you use in order to compute this probability? That's how we figure out how some of the underlying parameters are contributing.

• 8:41Emily Kwong?

  Gotcha. What are the limitations of that method? Just because everyone's bodies are so different and you have sampled hundreds of people, but not millions or billions of people on the planet. What additional data do you wish you had to make your predictive models better?

• 9:03Speaker 03

  Actually, that's where we're moving next. Right now, it's called the Human Immunome Project. The idea is we want to measure the entire world's immune system to increase representation of individuals with very different genetic backgrounds, very different exposure histories, facing very different kinds of stresses and so on. So that would help us to train these models to better represent all of the individuals on Earth in terms of their immune system.

• 9:31Emily Kwong?

  In the pursuit of gathering more data, and I read in David's article, the plan is to send immune monitoring kits all over the world. Are there going to be any kinds of like data privacy safeguards? Because we've seen so many health efforts in which people's data is then like sold to companies. So is that part of your plan at all with the Human Immunome Project?

• 9:55Speaker 03

  No, that's not part of the plan at all. Our mission is to make this openly available for researchers and anyone around the whole world. And second, we will be working with all the local scientists and jurisdictions about data privacy and everything. And in the sense that, of course, we want to protect the privacy of the participants. So the goal is not to take this data and sell the data to any specific entity or use it to benefit only a specific entity.

• 10:29Emily Kwong?

  OK, I want to go back to David's score, your immune health metric. Now, this was the score that was from the time of sampling. It's not like your forever score. It was 0.35 and...

• 10:44Emily Kwong?

  You were told what about it?

• 10:46Speaker 02

  Well, I was placed with a group of people about 20 years younger than me, meaning that my immune system seems to be about 20 years younger than my actual biological age.

• 10:56Emily Kwong?

  Nice.

• 10:57Speaker 02

  And the interesting thing about that is I do have other tests I'm taking right now that are telling me in various ways I am not that healthy, say, you know, in my kidneys and a couple of other places. But the question is, does that, does the health of my immune system override that?

• 11:15Emily Kwong?

  Yeah.

• 11:16Speaker 02

  So I'm on a quest here to find out what does all this mean, you know, for one person? And it's not really that it's all about me, although I'm interested in my own results. It's really I'm being able to play the role of the guinea pig, the human guinea pig here. And these are all questions that I think, you know, will be teased out over the next few years. And this is the first time in all of my testing for 25 years that I've actually had a study that begins to tell me what's going on in a holistic way in my underlying health.

• 11:46Emily Kwong?

  Yeah, you write, spotting a low immune health metric in a seemingly healthy person could make it possible to identify and start treating an illness before symptoms appear, diseases worsen, or tumors grow and metastasize. And you write about a world in which maybe John's test, tests like it, that the numbers could be available on like an app if people are regularly sampling. I mean, what impact could this have on medicine?

• 12:12Speaker 03

  Yeah, imagine a world where you could monitor how, how things are going in your body. And when there are signs that your body is going in the wrong direction, you can start to ask the question, can I modulate my immune system in particular? On the other end of the spectrum, there are rare disease patients. After years of bouncing around different medical specialties, they're undiagnosed, still undiagnosed. We can now pinpoint what's going on, what does, what does the immune system sense? And, and now can we move this person back to health?

• 12:45Speaker 02

  One of the major findings of John's work and others is a kind of paradigm shift.

• 12:53Speaker 02

  And it's really, I mean, I don't use this word ever, you know, because I'm a skeptical health journalist. But, you know, this is somewhat revolutionary that we're moving into this phase where I think it will shift medicine around. You know, why do some people get COVID? Why do some people not? Why do some people get allergies? Why do some people not? That's clearly has to do with your immune system. And probably your immune system may be more important than the actual severity of these threats.

• 13:23Emily Kwong?

  To learn more about the Human Immunome Project or to read David's full article about this in MIT Technology Review, check out our show notes. John Sang and David Ewing Duncan, thank you so much for coming on Short Wave.

• 13:34Speaker 02

  Thank you.

• 13:35Speaker 03

  Thank you very much.

• 13:38Emily Kwong?

  This episode was produced by Burleigh McCoy. It was edited by our showrunner Rebecca Ramirez and fact checked by Tyler Jones. Robert Rodriguez was the audio engineer. I'm Emily Kwong. Thank you for listening to Short Wave from NPR.

• 13:59Speaker 04

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