Arthur Allen is a distinguished freelancer who has written for many important publications including New York Times, The Washington Post, Slate and Mother Jones. He is the author of three fabulous books including one on vaccines that I highly recommend. Mr. Allen is health editor and writer at Politico.

His latest book is The Fantastic Library of Dr. Weigl: How Two Brave Scientists Battled Typhus and Sabotaged the Nazis. I had the privilege of reading the book recently and asking Mr. Allen questions about it. His book examines the creation of a typhus vaccine by two scientists, one Jewish and one Christian. Once a dreaded diseases that killed millions, today typhus has been banished from much of the planet. The two scientists he writes about plotted to give one version of the vaccine to concentration camp inmates that worked and one that did not to the Nazis.

Mr. Allen’s book brings us to many places that people may not have heard of before. He explores the fascinating world of interwar Lwow, now known as Lviv. Here Jews, Christians and people from all cultures mingled together in multicultural society that was largely destroyed when the Nazis marched through the city. During this time, the two scientists in Mr. Allen’s book collaborated in a celebrated laboratory that helped bring the science of vaccine development forward.

How did you come up with the idea for this book?

My book Vaccine (WW Norton, 2007) has a chapter titled “War is Good for Children.” It’s primarily about research funded by the U.S. military to develop vaccines. Armies are interested in vaccines because they want their troops to stay healthy. During World War II, military-funded labs came up with new vaccines against flu, Japanese encephalitis, yellow fever, and, finally typhus. I wrote a small amount about the U.S. typhus vaccine in the book and while doing the work I read a small amount about these strange vaccines they were making in Poland during the war. I didn’t spent much time on that while writing the book, but the names Weigl and Fleck stuck in my mind. A few years ago I decided to see if I could find out anything more about them, and I did.

Can you tell us about your research process?

I always start out reading whatever secondary literature I can get my hands on. In this case, that meant books about the Nazi doctors, and typhus, and Buchenwald, and Auschwitz, and the city of Lwow, which is now Lviv, Ukraine. I probably read all or parts of about 300 books—trying to gain generalized knowledge for a while and pretty soon tunneling into the literature that seemed most linked to what I was after.

Pretty soon I developed a sense of my book’s narrative arc, how it would move along, and then I tried to populate the chapters. In the case of this book it all takes place in Europe and a small bit in Israel. So I planned trips to the archives I thought would be important in Germany, Ukraine, Poland, Israel, France, Britain and Belgium, but also at Yale, Harvard, and a few other places stateside. And while I was planning those trips, in the meantime I found everything I could at the Library of Congress, the Holocaust Memorial Museum, the National Library of Medicine, and the National Archives, all four in the Washington area where I live.

I started studying Polish in 2011 but realized pretty quickly that I wasn’t going to get good enough at the language to do all the translations I needed. I puzzled over that for a while, but ended up making friends with a wonderful person, a sociologist at the University of Warsaw, and we made kind of a trade where she located and translated important documents for me, and I helped get her book published in the United States by giving it a very thorough edit. And I met the son of Hermann Eyer, one of the key German doctors in the book, in Munich, and he shared his father’s letters and some of his papers with me. I was also lucky to stumble upon a recently discovered private file of Erwin Ding-Schuler, the other key Nazi doctor in the book. Those papers had been brought back to Brussels by a Belgian Buchenwald POW and were found behind some shelves in 2010 in an archive there.

How did you choose the title of the book and what do you mean by the use of the word fantastic?

First, I wanted something that echoed “The Cabinet of Dr. Caligari,” something that evoked a wonderful or phantasmagorical world. And Weigl’s laboratory was fantastic in the sense that his procedure for making typhus vaccine is well beyond anything most of us could imagine—grotesque, perhaps, but something you might dream about. There’s a wonderful surrealist film called The Third Part of the Night by Andrzej Zulawski, whose father worked for Weigl. It depicts the Weigl lab, and if you haven’t read my book you’d have no idea that it isn’t an entirely surrealistic depiction. Also, Weigl was a fantastic person, a great man, whose work saved the lives of thousands of people. So his lab was fantastic in the simple sense of, “Great!”

What do you think people can learn from Dr. Weigl? Dr. Fleck? What is their ultimate legacy?

Both Fleck and Weigl, ultimately, were passionate scientists and humanists. And they were truthful and loyal. Weigl had a simple moral code. He was pro-life, in the sense that he thought people should have a chance to live and do their best, and he didn’t much care what their ethnicity was. He also enjoyed the finer things in life and wanted to survive, and wanted his friends to survive. He thought the Nazis were idiots and awful people who acted like savages, but people say he didn’t hate them. He did the best he could to help people, but he wasn’t an iconic hero because he didn’t commit some kind of self-sacrifice. He was sensible, believed in meeting people half way, and he set an example for the people who worked for him. As for Fleck, his most important legacy is his book The Genesis and Development of a Scientific Fact. The English version of it is not great, because the translator didn’t know biology and Fleck’s German wasn’t great, but I find it a tremendously inspiring book.

Fleck was a great humanist with an incredible capacity to see people benignly as members of different thought collectives or intellectual cultures. He even thought the Nazis were naughty, stupid children. He could float above it all, but at the same time he was very down to earth and on at least a few occasions saved his colleagues’ lives by thinking fast on his feet. His ideas outlived him and they are ideas to live by. I think about Fleck all the time. He would have made a great science journalist. And by the way, he was interested in the anti-vaccine movement—he wanted to get inside their heads, to understand what motivated them (I’m talking about the British anti-vaccinists of the turn of the 19th century). Fleck may even have written about the anti-vaccinists, but some of his papers were confiscated by the Israeli secret police when they arrested his friend Markus Klingberg in 1983 (Fleck had died in 1961), and those papers were either destroyed or are sitting on a shelf somewhere.

How does the process of creating a vaccine for typhus differ from contemporary vaccine creation?

Where to begin? All vaccines in that period were made by growing cultures of germs and either killing them, or weakening them through serial passage through different kinds of cultures. Typhus was hard to grow this way because it’s an intracellular bacterium that for the most part only really grows in lice or people. So it involved particularly odd or gruesome techniques – stretching the boundaries of natural growth and evolution – to produce it, whether it was made in eggs, rabbit lungs, or lice. Modern vaccines are designed.

Would you have volunteered to be a lice feeder?

Absolutely. In fact I offered to feed the lice in Lviv—there is a small colony there, the ancestors of Weigl’s original brood—but the scientists at the Ukrainian Hygiene Institute wouldn’t let me near them. They didn’t want the lice to get sick feeding on some weird American journalist.

Can you tell us about the history of Lwow/Lviv?

Many people, myself included, have never heard of the city before? Lviv is a treasure. Think Prague, or Vienna. It has great bones – wonderful hills and curving cobblestone streets and some beautiful buildings. It’s pretty rundown like a lot of the former Soviet Union but it still has wonderful charm. It was an Austro-Hungarian city, and a crossroads between West and East that always had a very mixed population. Before WWII it was about 45 percent Polish Catholics, 35 percent Jews, and the rest Ukrainians, Armenians, Czechs, Slovaks, Hungarians, a few Germans. And it was a very cosmopolitan city, from what I read, although its population was not enormous—maybe 350,000 at that time. While researching the place I found myself wishing I had been an idler there in the 1920s, strolling from café to café in a three-piece suit.

What do you think are the moral issues the book raises and point you hope people take away from the stories of Weigl and Fleck?

I think there are a couple of important lessons or things to think about. One is that as Fleck did it is important to try to see beyond your own thought community, to try to understand why other people—other countries, other religions, people with different belief systems–think the way they do. To avoid being rigid in one’s thinking. And it is important to realize that most people do the best they can, however irritating or idiotic they may seem. And you can’t expect people to act heroically all the time.