Lice, Life, and Leafhoppers: How Weigl’s vaccine creation influenced my virology research

This paper is dedicated to the memory of my brother Alfred who worked as a physician in the ghetto of Kolomyya. On September 1, 1942 my father was shipped with 8 000 Jews to be gassed in Belzec. Two weeks later my brother was arrested and his dead body returned to the ghetto a few hours later. On October 14 my mother was shipped to the Belzec extermination camp with the remaining 7 000 ghetto inhabitants. My wife and I survived the holocaust in refugee camps in Romania, but 138 closest relatives in Nazi occupied Europe perished in Treblinka, Belzec, and Auschwitz.

Bronia spoke Polish with my father and German with my mother. I grew into this system, only realizing that this bilingual system required writing not one, but two letters in two languages to my parents when I started my studies of agriculture at the Warsaw SGGW, the University of Biological Studies.My third language was Ukrainian, which was spoken by all peasants in Soroki, where our estate was located. I also had Ukrainian during the last 4 years of high school in Kolomyya, learning the Cyrillic script.
I was 13 years old when my brother ( Fig.1) came home from Lviv, where he was studying medicine and where his biology professor, Rudolf Weigl, described how he created the first, and until World War II the only vaccine protecting against exanthematic typhus. I was completely fascinated, hearing how professor Weigl was giving ene mas to individual lice, infecting them with Rickettsia provazekii. My brother described how Weigl inserted glass micropipettes into the anal opening of lice and how he maintained the inoculated insects on human volunteers for several days. Subsequently he removed the intestines from batches of 140 inoculated lice, crushed their intes tines in a tiny glass micro mortar with a few drops of forma lin, and obtained a single dose of his vaccine. Later I found out that this was the only existing available vaccine against trench fever until the end of World War II in Europe. The information about the currently used vaccine, produced first by Harold Cox in embryo nated chick eggs, was published in the United States but the publication did not reach Europe because of Pearl Harbor and the entry of the United States into the war.
My brother's description of Weigl's work was spell binding and I decided to become a medical researcher and try experiments similar to those carried out by the developer of the typhus vaccine. I received my baccalaureate degree at the top of my class and applied to the same medical school in Lviv, which my brother graduated from. I was not accepted because of numerus clausus, as only 10 Jewish students were accepted every year and I was not one of the lucky 10. I lost one year, stayed at home, and finished the 12 th year in the piano conservatory in Stanislaw (Ivanofrankivsk). I practiced daily at least 8 hours, but by the end of the year decided that I would not become a concert pia nist to compete with Arthur Rubinstein, and only become a piano teacher, which did not appeal to me. I decided to apply to the Warsaw SGGW, the University of Biological Sciences, where I was accepted in 1934. After 4 years, in 1938, I received the degree of Agricultural Engineer, the equivalent of an MS degree.
On May 24, 1935, I went with a group of SGGW students to Pulawy, the oldest Polish experiment station. The trip, during the 3-day holiday celebrated in Poland, Whitsuntide, was on the deck of an old boat on the Vistula River. We arrived early morn ing and walked through the ancient park of the Czartoryski estate towards the main station building. Across came a very nicely dressed girl, with a book in her hand. She paid no attention to the 20 students but when she passed me, at the very end of the group,she glanced for a fraction of a second at me. Her shiny black eyes struck me and a colleague noticed the shock that I experienced. He told me that he saw the same young lady in Warsaw in the company of the chemistry student who joined our group, and he offered to help me meet her that afternoon. During the following three years I was "going steady" with Irene Ludwinowska and after I graduated in 1938, we got married.

WORLD WAR II.
We returned to the family estate in Soroki where I worked till September 17, 1939. We were far from the war activities in the western part of Poland and only once saw a few planes and heard the thunder of bombing. Five German planes bombarded the bridge in Zaleszczyki, between Poland and Romania, but the bridge was not hit and the bombs fell on the Romanian side of the river. On September 17 we heard the announcement by Molotov, that the Soviet army was entering Poland to free the Ukrainian and Byelorussian peasants from the yoke of the Polish land owners. At noon 2 cars with Polish officers arrived and they asked where the Romanian border can be crossed. We thought that they were fighting, but they told us that they were fleeing the country. Our estate was 14 kilometers from the Romanian border and I decided to es cape across the nearby border to Romania. The nearest route was already occupied by Soviet tanks and we proceeded to the town of Kuty on the Czeremosz River, to cross the bridge linking Poland and Romania. However, Polish authorities prohibited civilians from crossing the bridge, permitting only uniformed armed forces to flee. We were in the car of the Polish major, Karol Krzyzanowski. He ordered his sergeant to remove from the trunk the major's overcoat which I put on. Then he removed his cap and placed it on my head. A moment later we reached the bridge, where the car was stopped and its pas sengers observed by a Polish officer. He dictated to his colleague: two majors, one ser geant…and who is she in the back? Major Krzyzanowski replied: This is my wife. Proceed! The officer saluted and for a moment I was a very young major, 24 years old, and my wife was Mrs. Krzyzanowski. On the Romanian side, in Wyznitsa, we found ourselves in an endless column of vehicles, very slowly moving through Romanian villages. Rumors were spreading that we will be interned in refugee camps and that all our possessions, including shoes and clothing, taken away. It was around midnight when high up on a hill I noticed lights in a large house. We decided to leave the long column of military vehicles, said good bye to the kindly major who helped us to cross into Romania, and walked up the hill to the mansion. It was the residence of a gentleman farmer, Mr. Orenski, who was a conductor and composer, as we found out later. There were already 200 Polish refu gees in his barn, but the lady who greeted us thought that we were relatives of her father in -law and received us very friendly. In the morning the owner of the estate told us that the rumors of interment in refugee camps were correct and that, if we would have conti nued on the main road, we would have been placed in such a camp. He directed us to a road leading to Chernivtse. Proceeding on the country road, we were stopped after an hour by a small group of Romanian solders and placed in a bus that took us to Chernivtse. The town was swarming with Polish refugees. All were sent to civilian refugee camps. My wife and I were interned in the town of Braila for the first year, and afterwards moved to Craiova, where we remained for the next 3 years. In Braila I learned how to make shoes on string soles and for the following 3 years I was a shoe maker, producing one pair of ladies' shoes per day. I also earned some money teaching piano. The refugee camps were disbanded when on August 24, 1944 the Soviet army occupied the country and expelled the Germans. We moved from Craiova to Bucharest, where I was accepted as a graduate student, to work on my Ph.D. thesis. With the help of the American attaché we were able to leave Romania for Sweden the end of 1946. On the basis of my agri cultural engineer degree we received a first preference emigration visa to the United States. On April 24, 1947 I was hired as a technician by L. M. Black at the Brooklyn Botanic Garden. Two years later I received my Ph.D. degree at Columbia University and was hired by L. O. Kunkel as his assistant at the Rockefeller Institute for Medical Research in New York City, soon to be changed into the Rockefeller University.

LEAFHOPPER INJECTIONS.
My childhood dream to follow Weigl's lice experi ments finally became a reality, although not with lice nor with enemy of tiny insects. Working with a plant virus, the wound tumor virus, I prepared very thin glass needles that I connected with metal needles, and injected extracts from diseased plants, or from viruliferous leafhopper vectors, into healthy leafhoppers (Fig. 2). At the Rockefeller University an adjustable insect holder was constructed, based on the lice holders in Weigl's laboratory. Virus transmission was successful and I published the results in Science in 1949. The mechanical virus transmission permitted the first titration of the wound tumor virus. It also provided evidence for the multiplication of several plantpathogenic viruses in their specific leafhopper vectors. I became actively involved in virus nomenclature and classification. The finding that little or no harm was observed in the virus carrying insects could suggest that these viruses originated as insect viruses and over long periods of evolution became harmless to their animal hosts, while their newer plant hosts were severely affected and often killed. Should these viruses be con sidered as plant, or as insect viruses? The affinity of vector-borne viruses to certain plant or animal hosts should not be used as a classifying criterion. I became a member of the International Committee for Virus Nomenclature (ICVN), but the controversial fights between plant and animal virologists continued and I lost interest in the fights and decided to devote my time to laboratory research and field work.