Russian scientists have developed a new vaccine strain against the highly pathogenic H5N1 avian influenza virus.
The strain closely matches currently circulating H5N1 variants and is designed to remain safe for both animals and humans. The work was carried out by researchers at the St. Petersburg State University of Veterinary Medicine and the A.A. Smorodintsev Research Institute of Influenza.
H5N1 continues to spread globally, causing mass die‑offs among domestic and wild birds and heavy economic losses. Its rapid evolution and ability to jump between species have reduced the effectiveness of older vaccines that no longer match circulating strains.
Using reverse‑genetics techniques, the scientists modified hemagglutinin and neuraminidase genes taken from an H5N1 virus isolated from a black‑headed gull in 2023, reducing the virus’s pathogenicity. These were combined with genes from a safe laboratory H1N1 strain to create a hybrid virus that replicates efficiently in chicken embryos.
In trials, chicks given two doses 14 days apart produced antibody levels against H5N1 that were ten times higher than the minimum required for protection, demonstrating strong immunogenicity, the foundation said.
