Periodic Reporting for period 1 - SOLVE (Sustainable COVID-19 Vaccination for Long-term Vaccine Immunity and Effectiveness)
Reporting period: 2024-01-01 to 2025-06-30
SOLVE is a European research initiative aiming to develop next-generation COVID-19 vaccines that provide broader, more durable protection against SARS-CoV-2, including current and future variants. Building on the limitations of existing vaccines, SOLVE explores four innovative vaccine platforms — dendritic cells (DC)-targeting, nanoparticles, MVA vectors and mRNAs-based vaccines — each designed to elicit strong and long-lasting immune responses.
The project brings together 10 partners from across Europe, combining expertise in immunology, vaccinology, clinical research, data science, and social sciences. By integrating these disciplines, SOLVE not only seeks to advance vaccine efficacy, but also to improve understanding of public perception and acceptance, supporting more effective communication and policy strategies in pandemic contexts.
The project brings together 10 partners from across Europe, combining expertise in immunology, vaccinology, clinical research, data science, and social sciences. By integrating these disciplines, SOLVE not only seeks to advance vaccine efficacy, but also to improve understanding of public perception and acceptance, supporting more effective communication and policy strategies in pandemic contexts.
During the first reporting period, the project successfully designed and manufactured vaccine candidates across the four platforms (DC-targeting, nanoparticles, MVA, and mRNA). Their immunogenicity was evaluated in vivo in murine models using homologous prime-boost strategies. Based on these results, one lead candidate per platform was selected for further development.
Preparations for an Experimental Medicine Trial (EMT) also progressed significantly. Regulatory submissions are underway in three European clinical centres. The trial design was refined, recruitment and sampling procedures harmonised, and participant information materials prepared. The trial will evaluate immune responses across multiple timepoints in healthy volunteers, comparing select vaccine candidates with two authorized vaccines.
In parallel, extensive preparatory work was conducted to set up all immunological analyses. Assays and data analysis pipelines for the characterization of innate and adaptive immune responses were established and validated, including high-dimensional cytometry for immune cell profiling, transcriptomic analyses, antibody and memory B cell assessments, and T cell repertoire evaluation. Expression and characterization of viral proteins were completed to support humoral response measurements, ensuring that once EMT samples are collected, high-quality, reproducible immunological data can be generated promptly.
On the data science front, a secure LabKey-based data warehouse (SOLVE data space) was established to receive and organize all experimental and clinical datasets. Processes and documentation for future data transfer were validated, enabling integrative analyses across vaccine strategies.
On the social science side, research focused on understanding vaccine hesitancy and public preferences. Literature reviews and systematic analyses identified key vaccine attributes and strategies to counter misinformation. Interviews with healthcare professionals highlighted barriers and facilitators to communication, while a Discrete Choice Experiment was designed to capture public preferences regarding both biomedical and contextual aspects of vaccines.
Preparations for an Experimental Medicine Trial (EMT) also progressed significantly. Regulatory submissions are underway in three European clinical centres. The trial design was refined, recruitment and sampling procedures harmonised, and participant information materials prepared. The trial will evaluate immune responses across multiple timepoints in healthy volunteers, comparing select vaccine candidates with two authorized vaccines.
In parallel, extensive preparatory work was conducted to set up all immunological analyses. Assays and data analysis pipelines for the characterization of innate and adaptive immune responses were established and validated, including high-dimensional cytometry for immune cell profiling, transcriptomic analyses, antibody and memory B cell assessments, and T cell repertoire evaluation. Expression and characterization of viral proteins were completed to support humoral response measurements, ensuring that once EMT samples are collected, high-quality, reproducible immunological data can be generated promptly.
On the data science front, a secure LabKey-based data warehouse (SOLVE data space) was established to receive and organize all experimental and clinical datasets. Processes and documentation for future data transfer were validated, enabling integrative analyses across vaccine strategies.
On the social science side, research focused on understanding vaccine hesitancy and public preferences. Literature reviews and systematic analyses identified key vaccine attributes and strategies to counter misinformation. Interviews with healthcare professionals highlighted barriers and facilitators to communication, while a Discrete Choice Experiment was designed to capture public preferences regarding both biomedical and contextual aspects of vaccines.
SOLVE has generated four novel vaccine candidates with promising immunogenicity, including platforms not yet widely used for COVID-19 vaccination. The head-to-head comparison of these platforms within a Experimental Medicine Trial is an innovative approach that will generate high-quality comparative data rarely available in vaccine development.
Advanced immunomonitoring tools have been put in place, enabling deep profiling of innate and adaptive immune responses in upcoming EMT participants.
On the social science front, the project has generated early evidence on how healthcare professionals perceive evolving vaccination needs and how vaccine attributes influence public preferences. These insights will help align communication strategies with population expectations and concerns.
To maximise impact, the next phase will focus on completing the EMT, analysing immune profiles, refining vaccine candidates, and leveraging social science insights to support the development of effective public engagement and communication strategies.
Advanced immunomonitoring tools have been put in place, enabling deep profiling of innate and adaptive immune responses in upcoming EMT participants.
On the social science front, the project has generated early evidence on how healthcare professionals perceive evolving vaccination needs and how vaccine attributes influence public preferences. These insights will help align communication strategies with population expectations and concerns.
To maximise impact, the next phase will focus on completing the EMT, analysing immune profiles, refining vaccine candidates, and leveraging social science insights to support the development of effective public engagement and communication strategies.