August 13, 2026
Transcript
Elizabeth McMahon
A lost lab notebook, an unexpected email, and a discovery that would illuminate how a vaccine saved millions. CAP fellow Dr. David Schwartz shares the story behind his find of a lifetime.
Dr. David Schwartz
It was like, you know, holding the Declaration of Independence or something like that. But even more so because it was unknown.
Elizabeth McMahon
This is Path News Network Daily edition from the College of American Pathologists. I'm Elizabeth McMahon with a special edition of the podcast. It's Thursday, August 13th. On July 18th, 1921, a newborn in Paris received the first dose of what would become the world's most widely administered vaccine. The infant was patient zero for the inoculation against tuberculosis or TB, a contagious respiratory disease that killed around one in seven people at the time, including the baby's mother the day before. It was a public health milestone that came more than two decades after French scientists Dr. Albert Calmette, a physician and microbiologist, and Dr. Camille Guérin, a veterinarian, began culturing TB bacteria at the Pasteur Institute outside Paris. More than four billion people would ultimately benefit from the meticulous lab work that produced the Basile Calmette-Guérin, or BCG vaccine, but handwritten evidence of their work largely disappeared. In early 2025, Dr. David Schwartz, a medical epidemiologist, pathologist, and manuscript collector, got an email. A friend of a friend in France had an old, unidentified lab notebook that looked like it warranted an expert's eye. Did Dr. Schwartz want to take a look?
Dr. David Schwartz
I said, Well, why not? Yeah, have him send it to you and you know, take a look at it. I I read French and you know, I'm being just curious. And so it was sent to my my friend who looked at it and said, Whatever this is, it's a terrible condition, and I don't even want to send it to you. There's no date, the pages are missing, nobody's author. There's no author, you know. I said, just send it to me.
Elizabeth McMahon
When the 69 loose pages arrived at his home, Dr. Schwartz, an expert in emerging infectious diseases, vaccines, and epidemiology, knew as soon as he started reading that it was one of Calmette and Guerin's original lab notebooks from their time developing the TB vaccine.
Dr. David Schwartz
I I was just amazed. It was like it was like, you know, holding the Declaration of Independence or something like that. But even more so because it was unknown.
Elizabeth McMahon
For Dr. Schwartz, the notebook was the find of a lifetime. Dr. Schwartz invited Lou Migliorini, an Emory University doctoral student who specialized in French literature focusing on medicine and TB to help him explore the delicate pages written in the distinct hands of Dr. Calmette and Dr. Guérin. The entries included the month and day, but not the year. The notes described a series of subcultures, or the transfer of microorganisms from one culture to a new one, followed by experimental inoculation of animals, including rabbits and guinea pigs.
Dr. David Schwartz
Bu t it's not toward the beginning where they're all die, but somewhere in the middle.
Elizabeth McMahon
Dr. Schwartz and Ms. Migliorini presented their discovery to the scientific community in a peer-reviewed paper published in the July edition of the journal Tuberculosis. They hypothesize that the notebook is most likely from the period between 1910 and early 1913. It’s the only original lab book known to exist on the BCG vaccine’s development.
For the wider TB research community, the notebook’s discovery provides insights into Calmette and Guerin’s methods. It also prompts new questions, says Dr. Marcel Behr, director of the McGill International TB Centre in Montreal.
Dr. Marcel Behr
Seeing the handwriting, seeing the way that people are organizing their experiments and describing it. At one point they called it impustine magnifique, you know, obviously they were using more colorful language than we do now. There was also at one point they talked about the bacteria had been resorbed. And I was like, hey, I wonder what that means? What exactly are they getting at? So trying to get at um the way they were thinking is very interesting. And then the other part that I wasn't sure is there or not is, you know, if you look at them, the manuscript as written, and you just do a search for things like hypothesis or questions or whatever, we we don't find that. So in the end, you're like saying, So what what were their hypotheses in 1906 and why did they do the experiment? It felt like it was a it was a lab book that described more what they did than why they did it, and maybe that was the style in that era.
Elizabeth McMahon
The BCG vaccine remains the sole TB inoculation licensed for use in humans and is relatively unchanged from its original formulation. In the past two decades, research has found the vaccine offers immunotherapeutic benefits for patients with invasive bladder cancer. Dr. Behr says the notebook is an exciting addition to the historical record of a devastating disease that still kills more than a million people a year, mainly in Southeast Asia and Africa.
Dr. Marcel Behr
I've studied BCG as a vaccine and how it was derived from Mycobacterium bovis. I used genomic methods in the past to try to figure out what happened between around 1908 and 1921. And I've been to the Pasteur Institute in Lille, where I've seen the original stocks of BCG that are in their museum. So for me, it was very cool to find out that somebody had found their lab books. And I guess one of my questions to myself was where should they have been? Do lab books belong at the institute? Do lab books end up in somebody's basement? And I kind of thought, hey, that's kind of interesting. I wonder where where all the other lab books are for all the other research that we use that's foundational to modern science.
Elizabeth McMahon
For now, the Calmette Guerin notebook remains with Dr. Schwartz, who is planning more publications on its contents amidst his pressing work on the Bundibugyo Ebola virus outbreak. He says the manuscript is a daily reminder of the impact a terrible disease and its life-saving vaccine have had on humanity.
Dr. David Schwartz
One of the major purposes for an immigration port like Ellis Island back in the late 1800s and early 1900s was to look for people coming in with tuberculosis, again, primarily from Europe, where it was endemic. So tuberculosis is just an incredibly historic disease. We have evidence going back thousands of years in the historical record of TV. So I I did I'm just very excited by it, frankly. I probably will never have the chance to find anything like this again in my lifetime. So it's it's it's pretty cool.
Elizabeth McMahon
That's all for today's special episode of the Daily Edition. Be sure to check the show notes for more information. Got a story you'd like us to cover on the Daily Edition? Write to us at stories at cap.org. We're back at 5 a.m. Eastern for another episode of the Daily Edition. I'm Elizabeth McMahon. Have a great day.