Lise Thiry (1921 – 2024)

Copyright: Service Public de Wallonie, J.L. Carpentier (with permission)

Lise Thiry was born in 1921 in Liège as the daughter of the famous poet Marcel Thiry. She was a gifted child, curious about everything. In secondary school, she was most interested in the arts. However, she heeded the advice of her father who counseled her to rather choose a field of science for study, since he believed that the arts depended on innate talent and could be developed without study. As a compromise, Lise started to study medicine in 1938 at the University of Liège. As only one of three women among 140 students, she was a trailblazer. Already at this early stage, she questioned why she could not spend more time talking to patients instead of dissecting corpses. Lise’s studies took place in troubled times, during the Second World War. During her internship, she had to take on heavy responsibility as an anesthetist to help take care of the victims of the bombing of Liège in 1943. When radiologist Georges Leroux kept finding signs of tuberculosis in young men that she could not see, she inquired about it, learning that the false diagnosis of tuberculosis rescued these men from forced labor in Germany. She then demonstrated her courage by becoming Leroux’ accomplice. In 1946, having finished her studies and being pregnant, Lise took on a position as a doctor in a prison for female collaborators. When stating her profession to the guardians, she was laughed at, “the image of the female doctor not yet [having] entered their mind”, as Lise commented [1].

After the birth of her son, in 1947 [2], she started to work at the Pasteur Institute of Brabant (since 2003 part of Sciensano) under the supervision of Paul Bordet, the son of Jules Bordet. Her first task was to cultivate the Bacillus Calmette-Guérin (BCG), the attenuated form of Mycobacterium bovis used as a vaccine against tuberculosis. By accident, Lise and her co-worker Marie-Paule Beumer found that BCG’s slow growth was sped up when adding zinc to the medium. The protein that BCG secretes when starved for zinc later became an important target for vaccine development. Together with Jacques Beumer, Lise then studied how the bacteriophage Pf lyses bacterial cells and published her first scientific article on her findings in 1949 [3].

In 1952, on the advice of Paul Bordet, she joined the lab of Prof. Sohier at the Pasteur Institute of Paris to learn how to infect chicken embryos with influenza virus. Back in Brussels, she then attempted to use these new techniques to further study the influenza virus, but to her surprise, she could not find any viral particles in the chicken embryos. After several experiments and discussions, she finally realized that she inoculated the embryos with a too high amount of viruses, causing interference. Indeed, a virus needs access to receptors on the surface of the cell to enter its host. When the number of viral particles becomes too large, all the receptors are blocked, hindering the virus’ entrance into the host cell. Lise and Jacques Beumer then decided to investigate whether this phenomenon could be exploited to protect hosts from viral infection. Lise tested in three different organisms whether antibodies raised against host tissue interfere with viral replication and found that anti-chicken serum reduced influenza virus infection in chicken embryos, anti-mouse serum reduced the severity of polio and meningitis in mice and antibacterial serum partially protected Escherichia coli from the Pf phage. This body of work became the material for her doctoral thesis. Her advisor, Paul Bordet, was at first reluctant to let her defend her thesis, stating that this “is difficult for a woman” [1]. But Lise persevered, as she describes in her autobiography: “The role of the woman is to assure the material wellbeing of the doctorand so that his brain works at its best. I played the exciting game that consisted of writing my thesis in between my household tasks” [1]. Because her chosen field of virology was so novel that her evaluators did not know it well, she took care to present her work clearly and even suggested interesting questions to her jury members. She successfully defended her thesis, entitled “Effects of anti-tissue sera on certain viral infections”, in 1955 [4]. The virology laboratory that she built up during that time not only developed diagnostic techniques but also carried out serological tests for hospitals, focusing on viruses that cause infant illnesses such as measles, mumps, varicella, and poliomyelitis as well as respiratory viruses. Given this experience, Lise’s laboratory was designated as a reference laboratory for virus identification [5].

Lise spent the following years traveling. In 1958, she applied for and received a Fulbright grant, which enabled a prolonged stay in Renato Dulbecco’s lab at Caltech. In 1961, she traveled to the former Czechoslovakia and Soviet Union and in 1965 visited Mao’s China together with Pieter De Somer and other scientists. Shortly afterwards, she was appointed professor at the Université Libre de Bruxelles.

In 1969, Lise became a cofounder of the study group for the reform of medicine (GERM). GERM’s goals included removing all financial barriers to health care as well as abolishing differences in rank between health care professionals. GERM also supported the right of abortion [6]. A few years afterwards, in 1973, Lise joined the socialist party, where she fought especially for the right of abortion and counseled several ministers of public health. In the same period, she also started teaching virology in the Faculty of Medicine at the Université Libre de Bruxelles.

In the first years of the eighties, more and more cases of severe immune deficiencies were reported among homosexuals and drug addicts. In 1982, the term ‘AIDS’ (acquired immune deficiency syndrome) was coined and in 1983 the virus was isolated by Luc Montagnier and his team. In the same year, Lise created a unit dedicated to the study of AIDS [5]. Two years afterwards, she isolated the virus from mother milk [7] showing that mothers can infect newborns with HIV, the causative agent of AIDS. In the same year, Lise also published a paper in Science that describes a test for AIDS in lymphocyte cell cultures using anti-sera against bovine leukemia virus [8]. By 1988, Lise’s AIDS lab was recognized as a national reference center for AIDS [5].

For her work on AIDS as well as her engagement for women’s rights, Lise Thiry was voted Belgian “Woman of the Year” in 1985. In the same year, she joined the Belgian senate to continue her fight for abortion [9] and was obliged to leave the Pasteur Institute of Brabant [2].

Lise also fought for immigrants’ rights. She was the godmother of the Nigerian Semira Adamou, who was suffocated by police officers in 1998. When asked by the director of the hospital Saint Luc to deny that the body of her goddaughter showed traces of violence, she refused [10]. Subsequently, she joined a non-governmental organization against the deportation of irregular immigrants, participated in demonstrations and finally represented her organization at the commission for regularization in 2000 [9].

In 2011, her extraordinary achievements were honored with the rank of Commander of the Walloon Merit [9].

In 2021, Lise celebrated her 100th birthday. She spent her entire life fighting against injustice and disease. Her outstanding scientific work and social contributions set an inspiring example.

Karoline Faust


[1] Lise Thiry. Marcopolette. Mémoires 1921-1977. Les Éperonniers Sciences pour l’homme. [2] Personal communication Paul Vandenbussche. [3] Jacques Beumer and Lise Quersin-Thiry. Degrés correspondants de sensibilité aux phages et de teneur des bactéries en récepteurs appropriés. Comptes rendus des séances de la Société de biologie et de ses filiales, 143, 1-3, 1949. [4] [5] [6] Thierry Poucet and Monique Van Dormael. 1964-1990: le Germ, pour un système de santé solidaire. Politique, 101, 2017. [7] Lise Thiry et al. Isolation of AIDS virus from cell-free breast milk of three healthy virus carriers. Lancet 2(8460), 891-892, 1985. [8] Lise Thiry et al. Bovine leukemia virus-related antigens in lymphocyte cultures infected with AIDS-associated viruses. Science 227(4693), 1482-1484. [9]