06 November 2026
Researchers led by Joanne Del Rosario have developed a computationally designed, multi-antigen mRNA vaccine (DVX-panH5Nx) that provides broad protection against diverse H5Nx influenza viruses.
Highly Pathogenic Avian Influenza (HPAI) H5Nx viruses continuously evolve and undergo reassortment, the exchange of genetic material between viral strains, as they circulate among avian and mammalian hosts worldwide. Historically, pandemic preparedness has relied on stockpiling strain-matched candidate vaccine viruses (CVVs). However, the remarkable evolutionary plasticity of these viruses, particularly in their surface proteins hemagglutinin (HA) and neuraminidase (NA), makes it difficult for conventional vaccines to keep pace. The emergence of distinct and highly virulent lineages, including clades 2.3.4.4b and 2.3.2.1e, underscores the limitations of relying on a single-strain defense strategy against an unpredictable pathogen.
To address these limitations, the research team used computational evolutionary models to engineer synthetic antigens rather than relying on a single naturally occurring viral isolate. They developed a lipid nanoparticle (LNP)-based mRNA vaccine, designated DVX-panH5Nx, encoding three key viral components: HA, NA (with particular emphasis on the N1 and N6 subtypes associated with severe human infections), and the matrix protein M2.
When evaluated in mice and ferrets, the latter being an established animal model for human influenza infection, DVX-panH5Nx demonstrated remarkable efficacy. The vaccine elicited broadly neutralizing antibodies and provided 100% survival following lethal challenges with highly divergent H5N1 clades representing two decades of viral evolution.
In contrast, conventional whole-inactivated CVV vaccines provided only 50%–67% survival when animals were challenged with antigenically mismatched strains. Surviving animals also experienced substantial weight loss and clinical disease. Furthermore, DVX-panH5Nx reduced viral replication in the lungs and spleen to below the limits of detection, substantially outperforming conventional vaccine comparators.
This multi-antigen approach represents a significant advance with potential implications for veterinary medicine and public health. By incorporating NA and M2, which provide additional immune targets beyond HA, the vaccine establishes multiple layers of immune protection. Even if mutations compromise recognition of the HA component, NA-directed antibody responses and M2-specific cellular immunity may help control infection and limit viral spread.
For the global poultry industry and pandemic preparedness planners, this scalable mRNA technology offers a promising alternative to conventional strain-matched vaccine strategies. Rather than continually reacting to emerging viral variants, it could enable the development and deployment of broadly protective vaccines designed to anticipate viral diversity.
Del Rosario, et al. (2026). Broad vaccine protection against globally diverse influenza A/H5Nx viruses. Cell Reports Medicine, 7(11), 103131.
