A Breakthrough in Flu Vaccination!

On May 9, 2025, scientists from Hong Kong made a groundbreaking announcement—a new needle-free nasal spray influenza vaccine that could revolutionize flu prevention by offering extensive protection against various human and avian flu strains.

Addressing Vaccine Limitations

Presented by the University of Hong Kong’s Li Ka Shing Faculty of Medicine (HKUMed), this innovative vaccine is designed to overcome the shortcomings of traditional flu vaccines, which often require yearly updates and only target a handful of strains.

Leo Poon Lit-man, chair professor of Public Health Virology at HKUMed, emphasized the pressing need for better flu defenses, noting the high burden influenza places on healthcare systems worldwide. He pointed out that existing seasonal vaccines usually cover only three selected strains, leaving us vulnerable to zoonotic viruses like the avian flu.

Why Nasal Sprays Are Game-Changers

This new intranasal vaccine aims to stimulate mucosal immunity right in the respiratory tract, providing a vital first line of defense against infections while also tackling needle-related hesitancy, especially among children who often dread shots.

Scientific Innovation at Its Best

Under Poon's leadership, the research team adopted two advanced strategies—genetic modification and codon usage optimization—to create live-attenuated influenza vaccines that can elicit strong immune responses against a range of flu virus subtypes. Poon explains that the first strategy involves altering human influenza viruses to present avian-like surface markers, which enhances immune responses through pre-existing antibodies. Team member Alex Chin Wing-hong elaborated on the second strategy, which involves silent mutations to mimic avian virus traits, maximizing safety without sacrificing efficacy.

Successful Trials and Future Aspirations

Preliminary mouse tests revealed outstanding protection against several strains, including human H1N1, H3N2, and avian H5N1/H7N9, with no adverse effects noted. As for the immediate future, Chin stated that the team plans to first focus on the two most significant influenza viruses, with an ambitious long-term goal of achieving broad-spectrum protection to fend off not only known viruses but also emerging threats.

Global Recognition and Next Steps

This remarkable technology has garnered accolades, including the prestigious Saudi Innovation Excellence Prize and dual gold medals at the 50th International Exhibition of Inventions in Geneva 2025. Patented and praised, it aligns with the World Health Organization’s urgent call for the development of next-generation universal flu vaccines.

With support from the Hong Kong Jockey Club Global Health Institute, the team is poised to advance their research into Good Laboratory Practice-standard studies, propelling the vaccine toward clinical trials.