Periodic Reporting for period 1 - LWNVIVAT (Limiting West Nile Virus impact by novel vaccines and therapeutics approaches)
Période du rapport: 2023-12-01 au 2025-05-31
West Nile virus (WNV) is one of the most widespread mosquito-borne pathogen in the world. While most WNV infected individuals (80%) are asymptomatic, 1% of the cases develop a severe illness with central nervous system affectation that, eventually, cause the death. The case-fatality rate increases in immunosuppressed individuals and in population over 60 years old (up to 30%) and, to date, there is no prophylaxis or treatment for this disease. Here, we aim to develop a novel WNV vaccine that protect from infection and/or WNV induced disease, and particularly, from neuroinvasion. In addition, we will generate WNV specific antibodies with therapeutic potential.
The pathway to impact is clear: if successful, LWNVIVAT will not only pave the way for a first-in-class WNV vaccine but also contribute to the global preparedness against emerging flaviviruses. It will provide a platform for rational vaccine design that could be adapted to future mosquito-borne viral threats. In doing so, it will reinforce European and global health security, especially in the context of an ageing population and increasing vector-borne disease risk due to environmental changes.
Although the project is driven by immunological and technological innovation, the integration of social sciences and public health perspectives will be considered in future phases to understand vaccine acceptance in elderly populations and guide communication strategies.
The pathway to impact is clear: if successful, LWNVIVAT will not only pave the way for a first-in-class WNV vaccine but also contribute to the global preparedness against emerging flaviviruses. It will provide a platform for rational vaccine design that could be adapted to future mosquito-borne viral threats. In doing so, it will reinforce European and global health security, especially in the context of an ageing population and increasing vector-borne disease risk due to environmental changes.
Although the project is driven by immunological and technological innovation, the integration of social sciences and public health perspectives will be considered in future phases to understand vaccine acceptance in elderly populations and guide communication strategies.
During the first reporting period, LWNVIVAT made significant progress across several WPs focused on rational design, production, and evaluation of WNV vaccine candidates as follows:
WP1 designed WNV E protein-based immunogens using in silico analyses, identifying conserved regions and minimizing cross-reactivity through targeted modifications. A consensus E protein targeting Strains 1 and 2 was generated and expressed efficiently. DIII-based immunogens were also developed using AI, showing improved expression and binding. A pool of T-cell epitopes was selected with broad population coverage and high predicted immunogenicity.
WP2 optimized expression systems in mammalian and insect cells. Protocols for purification and characterization were established, yielding proteins ready for immunogenicity testing.
WP3 focused on VLP-based formulations, enhancing antigen density and WNV mimicry. Key findings included improved VLP budding via signal peptides and the importance of intracellular processing. VLP production in insect cells was optimized.
WP4 established methods to assess immunogenicity using human tonsil organoids and blood cells. Protocols and ethical approvals were finalized in Spain and initiated in Italy. WP4 also contributed to T-cell epitope selection.
WP5 prepared in vivo immunogenicity studies in mice, obtaining ethical approval and defining protocols to assess humoral and cellular responses.
WP6 began generating monoclonal antibodies against WNV E protein. Human antibodies are being produced from naïve and immune libraries; mouse antibodies are in hybridoma evaluation.
WP7 prepared in vivo efficacy studies in immunocompetent and aged mice. Ethical approval was obtained, and experiments are planned for M24.
WP8 delivered a preliminary regulatory roadmap and began outlining GMP manufacturing considerations, pending further data.
WP9 developed initial strategies for exploitation, dissemination, and data management, aligned with RRI principles and project milestones.
WP1 designed WNV E protein-based immunogens using in silico analyses, identifying conserved regions and minimizing cross-reactivity through targeted modifications. A consensus E protein targeting Strains 1 and 2 was generated and expressed efficiently. DIII-based immunogens were also developed using AI, showing improved expression and binding. A pool of T-cell epitopes was selected with broad population coverage and high predicted immunogenicity.
WP2 optimized expression systems in mammalian and insect cells. Protocols for purification and characterization were established, yielding proteins ready for immunogenicity testing.
WP3 focused on VLP-based formulations, enhancing antigen density and WNV mimicry. Key findings included improved VLP budding via signal peptides and the importance of intracellular processing. VLP production in insect cells was optimized.
WP4 established methods to assess immunogenicity using human tonsil organoids and blood cells. Protocols and ethical approvals were finalized in Spain and initiated in Italy. WP4 also contributed to T-cell epitope selection.
WP5 prepared in vivo immunogenicity studies in mice, obtaining ethical approval and defining protocols to assess humoral and cellular responses.
WP6 began generating monoclonal antibodies against WNV E protein. Human antibodies are being produced from naïve and immune libraries; mouse antibodies are in hybridoma evaluation.
WP7 prepared in vivo efficacy studies in immunocompetent and aged mice. Ethical approval was obtained, and experiments are planned for M24.
WP8 delivered a preliminary regulatory roadmap and began outlining GMP manufacturing considerations, pending further data.
WP9 developed initial strategies for exploitation, dissemination, and data management, aligned with RRI principles and project milestones.
The results from WP1 have significant scientific and industrial impacts. The team developed several pipelines that will be available to the scientific community upon project completion, including specific controls for inter-family viruses and human cross-reactivity. These checkpoint systems are crucial, especially with emerging machine learning techniques for protein design, to mitigate potential adverse effects. Additionally, WP1 achieved important advances in industrial protein production by designing novel sequences that significantly enhance immunogen expression levels, which facilitates scalable manufacturing of any vaccines or products derived from the project.
WP2 has advanced the project’s scientific and translational goals by establishing a systematic, data-driven framework for the expression, purification, and biophysical characterization of candidate antigens. The integration of techniques such as HiBiT quantification, mass photometry, and surface plasmon resonance (SPR) ensures selection of only the most promising candidates based on expression yield, solubility, stability, and antigenicity. This rigorous methodology improves standards for early vaccine antigen screening and characterization, benefiting the broader scientific community. SPR confirmation of preserved neutralizing epitopes validates the design strategy and opens new avenues to study viral epitope structure-function relationships. Furthermore, WP2 has successfully transitioned selected variants to large-scale purification protocols adaptable to GMP conditions, supporting industrial translation by reducing risk and development timelines. The confirmation that multiple variants bind high-affinity neutralizing antibodies enhances prospects for both preventive and therapeutic applications, strengthening public health preparedness in regions at risk of WNV outbreaks. By achieving key milestones, WP2 confirms the viability of the project’s core concept—rational structure-based antigen design followed by experimental validation—and acts as a scientific and logistical cornerstone for subsequent work packages.
The achievements of WP3 have enabled the production of functional virus-like particles (VLPs) within the consortium, supporting ongoing vaccine development and antibody generation efforts. Although there is no measurable economic impact yet, these results are essential for advancing the scientific and technical aspects of the project.
WP2 has advanced the project’s scientific and translational goals by establishing a systematic, data-driven framework for the expression, purification, and biophysical characterization of candidate antigens. The integration of techniques such as HiBiT quantification, mass photometry, and surface plasmon resonance (SPR) ensures selection of only the most promising candidates based on expression yield, solubility, stability, and antigenicity. This rigorous methodology improves standards for early vaccine antigen screening and characterization, benefiting the broader scientific community. SPR confirmation of preserved neutralizing epitopes validates the design strategy and opens new avenues to study viral epitope structure-function relationships. Furthermore, WP2 has successfully transitioned selected variants to large-scale purification protocols adaptable to GMP conditions, supporting industrial translation by reducing risk and development timelines. The confirmation that multiple variants bind high-affinity neutralizing antibodies enhances prospects for both preventive and therapeutic applications, strengthening public health preparedness in regions at risk of WNV outbreaks. By achieving key milestones, WP2 confirms the viability of the project’s core concept—rational structure-based antigen design followed by experimental validation—and acts as a scientific and logistical cornerstone for subsequent work packages.
The achievements of WP3 have enabled the production of functional virus-like particles (VLPs) within the consortium, supporting ongoing vaccine development and antibody generation efforts. Although there is no measurable economic impact yet, these results are essential for advancing the scientific and technical aspects of the project.