A family of pioneers
Ruth Arnon was born Ruth Rosenberg in Tel Aviv on June 1, 1933, the youngest of three children, in what was then British Mandatory Palestine. Her roots in the land went back two generations. Her maternal grandparents had come from Russia in the 1880s with the First Aliyah, the first modern wave of Jewish immigration to the Land of Israel; they met on the boat, settled in Jaffa and later moved to Neveh Shalom, an early Jewish quarter near Jaffa that became part of Tel Aviv. Their daughter, Sarah Perlman, trained in one of the first classes of the Lewinsky Teachers Seminary and became a teacher.
Her father, Alexander Rosenberg, was born in Brest-Litovsk in 1898 and was brought to Petah Tikva at the age of six, when his whole family, great-grandparents included, left what is now Belarus and settled on a small orchard. He served in the Jewish Legion during the First World War and then studied in Vienna. Fascinated by electricity, in 1929, already the father of two, he moved the family to Toulouse, where he completed a degree in electrical engineering in three years and added a master's degree in mathematics. Back in Palestine he worked as an electrical engineer for the Electric Corporation until the 1960s. Arnon has always credited her own hunger to learn to his example.
A girl in a hurry
She was quick from the start. Her older brother and sister taught her to read and do arithmetic while she was still in kindergarten, and she was admitted straight into the second grade. She finished elementary school at 13, and her mother persuaded Barukh Ben-Yehuda, principal of the Herzliya Hebrew Gymnasium, Tel Aviv's celebrated high school, to let her enroll. By 15 she knew exactly what she wanted to do with her life: work on the scientific basis of medicine.
When she graduated she hoped to join a Nahal unit, the pioneering youth corps of the Israel Defense Forces, with her friends from the youth movement, but she was too young to be accepted. Instead she registered to study chemistry at the Hebrew University of Jerusalem. A year later she joined a special academic program that let her study during the academic year and do military training in the summers. After receiving her master's degree in 1955 she served for two years as an officer in the army. During that time she married Uriel Arnon, a chemical engineering student at the Technion in Haifa. The couple have two children, Michal, born in 1957, and Yoram, born in 1961.
Sela's first student
The turning point came when she heard that Ephraim Katchalski, later Ephraim Katzir and the fourth President of Israel, was looking for scientists for a new project at the Weizmann Institute of Science in Rehovot. She had been his student at the Hebrew University. "I mustered the courage to approach him," she recalled. Katchalski accepted her on the spot, but told her she would work with Michael Sela, a young chemist then about to return from postdoctoral training at the National Institutes of Health in the United States. In 1957 she became Sela's first doctoral student.
It was the start of one of the longest and most productive partnerships in Israeli science. Teacher and student published together for decades and rose together through the Weizmann hierarchy. Their early work set out to decipher the chemical basis of how the immune system recognizes proteins. They were among the first to use synthetic polypeptides, chains of amino acids built in the laboratory, as tools in immunology, and they prepared and characterized the first synthetic antigen, a man-made substance that provokes an immune response. They also built a small synthetic copy of one loop of the enzyme lysozyme, attached it to a synthetic carrier, and showed that it triggered antibodies that recognized the natural enzyme. From that result came the idea of synthetic vaccines, in which a precise piece of a germ is linked to a carrier to teach the body to defend itself, an idea that opened the road to modern peptide vaccines.
The experiment that failed the right way
In 1967 Arnon, Sela and a doctoral student, Dvora Teitelbaum, began a project on experimental autoimmune encephalomyelitis, or EAE, a disease that can be induced in laboratory animals by injecting a protein from the brain and that serves as a model for multiple sclerosis. MS is an autoimmune disease in which the body's own immune cells attack myelin, the insulating sheath around nerve fibers in the brain and spinal cord, causing symptoms that range from blurred vision and numbness to paralysis. The team's plan was to synthesize polymers that mimicked myelin basic protein, the brain protein thought to trigger the attack, and use them to cause the disease so that it could be studied more easily.
It did not work. The best characterized of their molecules, a random chain of four amino acids that they called Copolymer 1, or Cop 1, stubbornly refused to cause disease. After more than a year of trying, the scientists wondered whether it might be doing the opposite. It was. In 1971 they found that several of their copolymers strongly suppressed the MS-like disease in animals. "We didn't intend to develop a therapy for multiple sclerosis," Arnon said later. "It just happened in this serendipitous way." In the following years they showed that Cop 1 worked in guinea pigs, rabbits, mice and rats, could reverse the disease in monkeys, and did not simply shut down the whole immune system. Patent applications were filed in Israel and abroad between 1972 and 1974.
Thirty years to the pharmacy
Turning a laboratory surprise into a medicine took almost three decades. In 1977 the first small trial took place at the Hadassah-Hebrew University Medical Center in Jerusalem, led by Oded Abramsky, a former doctoral student of Arnon's: four patients in the final stages of MS received Cop 1 without major side effects. Then came what Arnon called "the peddling period," when she attended almost every MS conference she could and talked to anyone who would listen, trying to persuade doctors to run larger trials. Two answered: Helmut Bauer at the University of Göttingen in Germany and Murray Bornstein at the Albert Einstein College of Medicine in New York.
Bornstein's double-blind trial recruited 50 patients from several hundred interviewed and lasted more than three years. Arnon telephoned him at least once a month for news. In 1987 the results appeared in the New England Journal of Medicine: Cop 1 reduced the number of attacks in patients with relapsing-remitting MS, with minimal side effects. That same year the Weizmann Institute licensed the drug to Teva Pharmaceutical Industries, then an upstart Israeli generic drug company, for which it became the first original drug. Teva tested it at 11 medical centers across the United States, submitted it to the Food and Drug Administration on June 14, 1995, and on December 23, 1996, the FDA approved it under the name Copaxone, with the generic name glatiramer acetate. It was one of the first Israeli-developed medicines to win American approval.
How patients benefit today
Multiple sclerosis affects millions of people worldwide, most often striking young adults. Copaxone was one of the first generation of disease-modifying drugs, medicines that aim to change the course of the illness rather than only treat its attacks. Given by injection under the skin, it is approved to reduce the frequency of relapses in relapsing forms of MS, including in people who have had a first episode suggesting the disease. Its exact mechanism is still being studied, much of it in Arnon's own laboratory, but it appears to act as a decoy for the immune cells that attack myelin and to shift the immune response toward cells that calm inflammation rather than fuel it. Its long safety record has made it a common choice for long-term treatment.
The drug reached an enormous number of people. The Weizmann Institute has reported that at one point some 40 percent of the world's MS patients were taking Copaxone, and it became one of the biggest pharmaceutical success stories in Israeli history. Since the original patent expired in 2015, lower-cost generic versions have been sold in the United States and elsewhere, and a longer-acting dose allows injections three times a week instead of daily. Glatiramer acetate is on the World Health Organization's List of Essential Medicines. Its story also became a model: proof that curiosity-driven work on how the immune system recognizes molecules can produce a treatment for an autoimmune disease, and a template for designing drugs based on the specific target of other autoimmune conditions.
Vaccines, leadership and teaching
Arnon did not stop with MS. Building on her early work on synthetic antigens, she asked whether antibodies against carefully chosen pieces of a virus could protect against it. Each year flu vaccines must be redesigned because the virus's surface proteins keep changing, so she set out to build a vaccine from segments that stay the same across many strains. After some 15 years of experiments, the company BiondVax was founded in 2003 to develop her universal flu vaccine candidate, M-001, which went through several human trials that showed it was safe and stimulated the immune system. A large late-stage trial reported in 2020, however, found no clear protection against flu illness. She has also worked on cancer vaccines and directed the Weizmann Institute's MacArthur Center for research on tropical parasitic diseases, and she has published more than 400 articles, chapters and books.
At the Weizmann Institute she headed the Department of Chemical Immunology, served as Dean of the Faculty of Biology and as Vice President, and later as Vice President for International Scientific Relations. Abroad she was President of the European Federation of Immunological Societies, Secretary-General of the International Union of Immunological Societies and a member of the European Union Research Advisory Board, and she served on a World Health Organization task force in the 1970s. In 2010 she became the first woman president of the Israel Academy of Sciences and Humanities, which advises the government on science, serving until 2015. She has advised Israel's presidents on science and co-chairs the UK-Israel Science Council. She and her husband also gave a major gift to create the Ruth and Uriel Arnon Science Education Campus at the Weizmann Institute, home to a center where hundreds of talented high-school students from Rehovot and Ness Ziona study physics with teachers who hold advanced science degrees.
Jewish roots
Arnon belongs to a family woven into the story of the Jewish return to the Land of Israel. Her mother's parents arrived from Russia with the First Aliyah in the 1880s; her father's family came from Brest-Litovsk in 1904 to farm an orchard in Petah Tikva, one of the earliest Jewish agricultural settlements; and her father served in the Jewish Legion, the volunteer battalions of Jewish soldiers that fought with the British in the First World War. She was educated at the Herzliya Hebrew Gymnasium, the first Hebrew high school, and she is profiled in the Shalvi/Hyman Encyclopedia of Jewish Women published by the Jewish Women's Archive.
The sources do not describe her religious practice; her own story is one of Hebrew-speaking Tel Aviv, army service and science in a young state. She has long spoken of investing in the next generation of Israeli scientists, but the fruit of her work has gone to everyone: Copaxone is prescribed to people of every background on every continent where MS is treated.
Honors and legacy
Arnon's honors include the Robert Koch Prize in Germany in 1979, the Jiménez Díaz Award in Spain in 1986, France's Legion of Honor in 1994, the Wolf Prize in Medicine and the Rothschild Prize in 1998, and the Israel Prize for medical research in 2001. She was elected to the Israel Academy of Sciences and Humanities in 1990, to the European Molecular Biology Organization and, in 2009, to the American Philosophical Society, and in 2021 she was named an honorary Officer of the Order of the British Empire. The Wolf Prize jury honored her and Sela together for introducing synthetic polypeptides into immunology, for opening the road to synthetic vaccines, and for developing Cop 1.
She and Uriel have lived on the Weizmann campus for decades, and she has held the Paul Ehrlich Chair of Immunology there. Her legacy rests on a rare combination: deep basic research into how the immune system tells friend from foe, and the stubbornness to carry one unexpected result through nearly 30 years of trials until it reached patients. For people living with multiple sclerosis, that persistence has meant fewer attacks and, for many, longer stretches of ordinary life.
Sources & further reading
Ruth Arnon, Shalvi/Hyman Encyclopedia of Jewish Women, Jewish Women's Archive · Cop 1 (Copaxone): The Story of a Drug, Weizmann Institute of Science · Ruth and Uriel Arnon, Weizmann Compass, Weizmann Institute of Science · Ruth Arnon, Wolf Prize in Medicine 1998, Wolf Foundation · Glatiramer acetate, Wikipedia · Researched from the sources above and checked against them. Spotted an error? Tell us.
A life of tikkun olam. This is part of tikkun olam, the Jewish idea of repairing the world, and every one of us can add to it.