Collaboration between immunologist Eric Muraille and microbiologist Xavier De Bolle awarded GSK Vaccines Prize 2025

Prof. Eric Muraille and Prof. Xavier De Bolle have just been awarded the 2025 GSK Vaccines Prize by the Royal Academy of Medicine of Belgium for their work entitled “Rational development of safer live attenuated vaccines against brucellosis using transposon sequencing”. Each year, this prestigious prize is awarded to one Dutch-speaking and one French-speaking researcher for outstanding contributions to the fields of vaccinology or immunology. The award ceremony took place on September 20, 2025. 

Prof. Eric Muraille, Research Director at the FNRS, is affiliated to the Parasitology Lab of ULB and the ULB Center for Research in Immunology (U-CRI). He is also a scientific collaborator at UNamur, where he works in close collaboration with Prof. Xavier De Bolle (NARILIS, URBM). Together, they investigate various aspects at the interface between the host and Brucella, the bacteria responsible of brucellosis, a worldwide zoonosis. Their interdisciplinary research bridges immunology and microbiology and relies on a longstanding partnership between ULB and UNamur. This partnership combines the expertise and research infrastructure of both institutions, including ULB’s animal facility and immunohistofluorescence microscopy, and UNamur’s flow cytometry platform and BL3 lab. 

One of their joint projects focuses on the development of a safer live attenuated vaccine (LAV) to protect animals against brucellosis. While currently available LAVs provide satisfactory protection for livestock, they have serious drawbacks. The main issue is that they persist for years in vaccinated animals. The vaccine strains can cause abortions, leading to significant economic losses and may be excreted in milk, posing serious public health concerns since these LAV strains are fully virulent for humans.

First-generation LAVs were generated by empirical methods such as random attenuation by successive passages. The work led by Eric Muraille and Xavier De Bolle demonstrates the effectiveness of a transposon sequencing (Tn-seq) approach to rationally develop safer LAV candidates. Using a mouse model that mimics natural infection via the respiratory route, the researchers applied Tn-seq to identify genes essential for Brucella multiplication in key organs: the lungs (the natural entry site) and the spleen (a major reservoir during the chronic phase of infection). Deletion of these essential genes offers a targeted strategy to weaken the strains and develop improved LAVs. For further details, read the following publications: Vitry et al., 2014; Hanot Mambres et al., 2016; Sternon et al., 2017; Demars et al., 2019; Potemberg et al., 2022 and Barbieux et al., 2024.