ROTTERDAM, October 30, 2025: Scientists at Erasmus University Medical Centre in the Netherlands have developed a single-dose vaccine that could provide broad protection against all known and emerging strains of highly pathogenic avian influenza A(H5), commonly referred to as bird flu. The vaccine, described in the journal Nature, is being hailed as a breakthrough in the global effort to strengthen defences against influenza viruses with pandemic potential. The research team, led by Mathilde Rochard, created a high-resolution three-dimensional map showing how the H5 haemagglutinin (HA) protein has evolved over several decades.
The HA protein enables the virus to bind to host cells and is the key target of immune responses in influenza vaccines. By mapping the antigenic evolution of the H5 subtype, the scientists identified the central point that connects all existing and potential future H5 variants. Using this data, the team designed a synthetic version of the HA protein that sits at the “antigenic centre” of the H5 family. The synthetic antigen was engineered to resemble all known variants as closely as possible without matching any one strain specifically. This approach aims to induce an immune response that recognises and neutralises a wide spectrum of H5 viruses.
Animal trials conducted using ferrets, which are considered a reliable model for human influenza infection, demonstrated that the vaccine produced strong immunity. The single-dose shot protected the animals against multiple, genetically distinct H5 strains. It also provided protection against two additional strains that were not included in the vaccine’s original design. Researchers reported that the immune response was comparable to that achieved with strain-specific vaccines, indicating broad and durable cross-protection.
Vaccine aims to provide lasting protection against H5 outbreaks
The findings mark a significant development in influenza research. Current flu vaccines are typically strain-specific and must be reformulated annually to match circulating viruses. This new approach, which targets a stable antigenic centre instead of rapidly changing outer proteins, could potentially allow for longer-lasting protection and reduce the need for frequent vaccine updates. The study’s authors confirmed that further testing will be required to assess the vaccine’s safety and effectiveness in humans. Clinical trials have not yet begun, and the timeline for regulatory review has not been established. The research remains at the proof-of-concept stage, but its results are regarded as an important step toward developing a universal vaccine for avian influenza.
Global health agencies have expressed concern in recent years over the increasing spread of H5 viruses among wild birds and mammals, including sporadic infections in humans. Outbreaks of H5N1 and other avian flu subtypes have led to the culling of millions of birds across Europe, Asia, and the Americas. The virus’s ability to mutate rapidly and cross species barriers poses an ongoing threat to both public health and the poultry industry. According to data from the World Health Organization (WHO), the H5N1 strain has caused hundreds of human infections since its emergence in 1997, with a high case fatality rate.
One-shot vaccine could reduce need for yearly flu updates
Although sustained human-to-human transmission has not been observed, the potential for adaptation remains a concern. Vaccines that provide cross-protection against multiple variants are therefore a key focus of influenza research worldwide. The Erasmus University team’s work aligns with international efforts to develop next-generation influenza vaccines that can preempt viral evolution rather than react to it. If future trials confirm the findings, the one-shot vaccine could play a critical role in reducing the impact of avian influenza outbreaks and improving global pandemic preparedness. The breakthrough also reinforces the importance of cross-border scientific collaboration in addressing rapidly mutating viral threats through innovative immunization strategies. – By EuroWire News Desk.