Podcast Summary: Short Wave – "The Future Of Immune Health Might Be Here"

Host: Emily Kwong (NPR)
Guests: David Ewing Duncan (science writer, “experimental man”), John Tsang (Professor of Immunology, Yale University)
Date: November 12, 2025
Length: ~15 minutes

Overview

This episode dives into the cutting-edge science of immune health assessment. Host Emily Kwong is joined by journalist David Ewing Duncan and immunology professor John Tsang to discuss the development of a new "immune health metric". The conversation explores how this metric—developed by Tsang and colleagues at Yale—could change the way we understand, measure, and potentially improve our immune health, and what it might mean for the future of medicine.

Key Discussion Points & Insights

1. Meet the “Experimental Man”

• David Ewing Duncan has spent his career undergoing cutting-edge tests to better understand human health ("I was one of the first humans to have my DNA sequenced for a story for Wired magazine." – David, 00:28).
• Over decades, he has collected 70TB of personal health data, spanning genomics, proteomics, microbiomics, MRI scans, and more (01:01).

2. What Is Immune Health And Why Does It Matter?

• Kwong describes the “immunome”: the layers of genes, proteins, and cells that make up our immune system (01:50).
• There are 1.8 trillion immune cells in our bodies, with many constantly patrolling for threats (02:11).
• Tsang emphasizes that immune health is as—or more—important than biological age and is central to how we recover from illness (01:55, 02:20).

3. Traditional Versus New Approaches to Measuring Immunity

• Traditional Test: The Complete Blood Cell Count (CBC) just measures basic blood cell numbers, giving a vague snapshot of immune status (05:28).
  • "The CBC just tells you there's something going on in your body... 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." – David (06:11)
• New Approach: Tsang’s “Immune Health Metric” draws from much deeper analysis, looking at holistic deviations in the immune system (06:38).

4. How the Immune Health Metric Was Developed

• Tsang’s team studied both healthy people and those with rare immune defects to create a comprehensive “map” of the immune system, identifying connections and deviations from health (06:38).
• They also used artificial intelligence to analyze patterns and create a meaningful, comparative score:
  • “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...” – John (07:58)
• This score is not static; it gives a snapshot of immune health at the time of sampling (10:39).

5. Sampling, Data, and the Next Steps

• The limitations of the metric are primarily in data diversity; the Human Immunome Project aims to broaden immune measurement globally with better representation (09:13).
• They are attentive to privacy concerns:
  • “Our mission is to make this openly available... 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.” – John (10:05)

6. David’s Test Results and What They Mean

• David’s immune health score was 0.35, which, after explanation, placed him with a group about 20 years younger than his actual age (11:05).
• Interestingly, other health indicators for David were not as positive (e.g., kidney issues), raising important questions: Does immune fitness override or reveal more than organ-specific tests? (11:06).
• David highlights that catching low immune scores in otherwise healthy people could help detect illness earlier (11:55).

7. Big Picture: Future of Medicine

• Tsang foresees a world where regular immune health monitoring could inform early intervention and drive highly personalized treatments (12:21).
• Potential for rare diseases: Immune health mapping could help diagnose patients who have defied standard diagnostic approaches (12:21).
• Duncan sums it up as “somewhat revolutionary,” suggesting the immune system’s health may underpin why people react differently to diseases like Covid or allergies (12:55).

Notable Quotes & Memorable Moments

• On the importance of immune health:

  “It’s probably the most important system in our bodies. It literally decides if we’re going to be able to heal ourselves...”
  — David Ewing Duncan (01:55)

• On the new approach’s holistic nature:

  “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.”
  — David Ewing Duncan (07:34)

• On privacy and global data collection:

  “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.”
  — John Tsang (10:05)

• On the potential for early intervention:

  “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...”
  — Emily Kwong quoting David’s article (11:55)

• On the paradigm shift in medicine:

  “I don’t use this word ever, you know, because I’m a skeptical health journalist. But, you know, this is somewhat revolutionary...”
  — David Ewing Duncan (12:55)

Important Timestamps

• 00:28 – David reflects on being “experimental man”
• 01:12–02:20 – The role and scale of the immune system
• 05:28–06:23 – Why CBCs aren’t enough
• 06:38–08:51 – How the immune health metric is developed & AI's role
• 09:13–10:05 – Human Immunome Project and privacy considerations
• 10:39–11:06 – David’s test results and what they reveal
• 11:55–13:32 – Potential of early immune detection and the future impact on medicine

Conclusion

This episode highlighted both the promise and the complexity of personalized immune health. Through the story of David Ewing Duncan and the pioneering work of John Tsang’s lab, listeners get an accessible, engaging exploration of how immune “scores” might become a standard tool for predicting, diagnosing, and perhaps even preventing disease long before symptoms emerge. The conversation is candid about limitations, ethical considerations, and the real-world impact such science could have—an exciting glimpse into the future of medicine.