An AI-designed, mRNA-based avian influenza vaccine provides broad-spectrum protection against H5Nx viruses.

Dr. Salah Mahdi Hassan, Consultant in Poultry Health and Diseases.

12/ 11/ 2026

Researchers from the University of Cambridge, in collaboration with DIOSynVax (a university spin-off company) and other partners, have designed a multi-antigen mRNA vaccine—dubbed “DVX-panH5Nx.” In animal studies, the vaccine provided complete (100%) protection against lethal challenges from various strains of the H5N1 virus—strains that are currently circulating globally. This performance surpasses that of traditional vaccine candidates, which are typically designed to target specific, matching strains. The approach taken by the Cambridge research team—utilizing AI-driven engineering to develop vaccines with broad-spectrum protection—is designed to remain effective against a wide range of both current and future viral variants. A study recently published in the scientific journal *Cell Reports Medicine* indicates that a new, digitally designed, multi-antigen mRNA vaccine has outperformed traditional avian influenza vaccines—which consist of a single strain of whole-inactivated virus (WIV) and primarily target the hemagglutinin (HA) protein from a single isolate. Because these vaccines are based on viral strains that are in a constant state of evolution, they can rapidly lose their efficacy when faced with heterologous strains, those that have undergone antigenic drift, or those that have experienced genetic reassortment.

To overcome these evolutionary challenges, researchers employed artificial intelligence to develop a “Digitally Immune-Optimized Synthetic Vaccine” (DIOSynVax). In creating this vaccine, the researchers utilized a digital application for phylogenetic modeling—reconstructing and analyzing the evolutionary history (lineage relationships) of viral genes sourced from global sequence repositories, such as the Global Initiative on Sharing All Influenza Data (GISAID) and the NCBI. This allowed for the computational design of antigens that incorporate both conserved and critical variable antigenic determinants.

The resulting vaccine platform, designated DVX-panH5Nx, consists of two polycistronic mRNA constructs encapsulated within lipid nanoparticles, structured as follows:

Construct 1: Encodes the computationally designed antigens—specifically the protein… DVX-H5-1 (representing viral clades that have infected humans, both historically and contemporarily), the DVX-N1 protein, and the DVX-M2 protein—with these proteins linked to one another via self-cleaving 2A peptides.

Construct 2 encodes the DVX-H5-2 protein (designed to track the rapid evolutionary trajectory of the 2.3.4.4 clade), the DVX-N6 protein, and the DVX-M2 protein. This polycistronic architecture enables the coordinated expression of the HA, NA, and M2 proteins within the same host cell into which the genetic material has been introduced; this, in turn, simplifies the manufacturing process and quality control for the vaccine.

The results of this study demonstrate the potential of AI-driven vaccine design to generate broad-spectrum protective immunity in vaccinated hosts against evolving biological threats.

Immunological studies conducted in mice and ferrets have shown that these vaccines possess high antigenicity. Specifically, the DVX-panH5Nx vaccine induced very high titers of neutralizing antibodies against a wide range of genetically divergent viral strains, including the ancestral clade 1 and clade 2.3.2.1e. And several viral subclades within clade 2.3.4.4, including viral isolates of genotype D.1.1, which have been recently isolated from cattle and humans.

On the other hand, conventional, fully inactivated vaccines—including those based on the A/Vietnam/1194/2004 and A/Astrakhan/3212/2020 strains—demonstrated a limited capacity to elicit neutralizing antibodies, with their efficacy restricted to challenges by viral strains belonging to specific sub-lineages. Furthermore, immunological study results indicated that, in contrast to fully inactivated vaccines—which showed only a modest immune response in terms of neuraminidase (NA) inhibition—the DVX-panH5Nx vaccine successfully induced high and robust levels of neuraminidase-inhibiting (NI) antibodies, effective against a diverse range of heterologous N1 and N6 strains. While conventional, fully inactivated vaccines may only provide immunity against a single avian influenza viral strain, this innovative new vaccine—characterized by a broad antigenic spectrum—offers protection against a wide range of genetically diverse viral strains.

Challenge study results indicated that mice immunized with the DVX-panH5Nx vaccine demonstrated very high resistance (a 100% survival rate). They remained completely unaffected—showing no weight loss or clinical signs—even when exposed to lethal doses of three antigenically distinct H5N1 viruses: A/Vietnam/1203/2004 (clade 1), A/Cambodia/NPH230032/2023 (clade 2.3.2.1e), and A/British Columbia/PHL-2032/2024 (clade 2.3.4.4b).

In contrast, the conventional, fully inactivated vaccine (clade 2.3.4.4b) yielded a 50% survival rate in mice against the clade 1 strain and a 67% survival rate against the clade 2.3.2.1e strain. It should be noted that, by the fourth day post-viral challenge, mice vaccinated with the DVX-panH5Nx vaccine exhibited extremely low—effectively zero—viral loads in both the lungs and the spleen.

Regarding the challenge in ferrets, the study demonstrated that those vaccinated with DVX-panH5Nx and subsequently exposed to a lethal dose of a highly pathogenic avian influenza virus (strain A/chicken/Italy/23VIR3799-1/2023, clade 2.3.4.4b) showed a 100% survival rate. The animals exhibited only very mild clinical symptoms, and there was no evidence of viral spread beyond the lungs—specifically, no virus was detected in the liver, spleen, or pancreas. In contrast, the group of ferrets vaccinated with a conventional, fully inactivated vaccine (clade 2.3.4.4b)—which were also challenged with the same virulent virus—exhibited a 50% mortality rate by the eighth day post-challenge.

These results demonstrate that the rational design of multivalent antigens can overcome the fundamental limitations of vaccines based on a single isolate that rely exclusively on the hemagglutinin (HA) protein. Consequently, this study highlights the potential advantages of a dual-action approach: targeting viral entry (via the HA protein) to elicit neutralizing antibodies, while simultaneously inhibiting the shedding of the challenge virus (via the neuraminidase, or NA, protein). This provides a comprehensive, two-pronged immunological defense mechanism.

Ultimately, these next-generation vaccines represent a paradigm shift for national biosecurity and for a more resilient “One Health” public health system. This approach enables us to prepare for an immediate response to viral epidemics and pandemics—moving beyond the current, largely reactive stance, where we are often forced to respond using vaccines designed for viral strains that have already evolved.

reference

Del Rosario et al. (2026). Broad vaccine protection against globally diverse influenza A/H5Nx viruses. Cell Reports Medicine, 7(11), 103131.