Last December ended the “Inhaled RNA Vaccines Against Tuberculosis” (VIRTB) project. Funded by the PERTE de Salud de Vanguardia, this project was a collaboration involving researchers from the University of Zaragoza, the NanoBioCel group at the University of the Basque Country, and our team.

During its nearly two-year span, the VIRTB project achieved significant breakthroughs in the development of messenger RNA (mRNA) vaccines against tuberculosis—one of the deadliest infectious diseases globally. Using next-generation ionizable lipids designed by Certest to encapsulate mRNA into lipid nanoparticles (LNPs), optimized vaccines were formulated to enhance the stability, bioavailability, and expression of mRNA, thereby boosting their immunogenic potential.

In partnership with the University of Zaragoza, strategic selection of Mycobacterium tuberculosis antigens with high immunogenic potential was carried out. After optimizing these antigens for efficient expression in eukaryotic cells, various LNP formulations encapsulating combinations of antigenic mRNAs were developed. Preclinical trials in mice demonstrated that these formulations induced a robust immune response—both in antibody production and T-cell activation. Notably, the newly developed vaccines, when administered in repeated doses, matched the protection offered by the BCG vaccine (currently the only approved vaccine for tuberculosis) and even enhanced its efficacy when used as a booster.

Simultaneously, the University of the Basque Country focused on optimizing candidate LNP formulations for inhaled administration—a promising strategy for direct immunization of the lungs, the primary site of tuberculosis infection.

These results position the VIRTB project as a success in advancing mRNA-based vaccines, opening new opportunities to combat tuberculosis and other infectious diseases through nucleic acid technologies.