Russian researchers announce new variant of H5N1 bird flu vaccine

Scientists in Russia have developed a new variant of the H5N1 bird flu vaccine, adapted to strains currently circulating globally. The announcement was made by the Russian Science Foundation, as quoted by the Xinhua news agency. According to the Russian institution, the vaccine is designed to provide a high level of protection against contemporary H5N1 viruses and, at the same time, be safe for both animals and humans. Representatives of the Russian Science Foundation stated in a statement published on its official website that the new vaccine "exactly matches” the viral variants currently in circulation, an essential aspect in the context of the high genetic variability of the H5N1 virus. The study was conducted by researchers from the Faculty of Veterinary Medicine of St. Petersburg State University and the A.A. Smorodintsev Influenza Research Institute, one of the leading Russian institutions specializing in the study of influenza viruses.

• New vaccines against H5N1

The highly pathogenic avian influenza H5N1 continues to circulate worldwide, causing mass mortality among domestic and wild birds, as well as significant economic losses in the agri-food sector. In addition, the virus is known for its ability to cross the species barrier, which raises concerns about the potential risk to human health. Experts point out that older vaccines lose their effectiveness as the virus mutates and no longer corresponds to the dominant strains. To obtain the new vaccine variant, the researchers used an advanced reverse genetics technique, which allows for controlled modification of the viral genome. The genes encoding hemagglutinin and neuraminidase were extracted from an H5N1 virus isolated in 2023 from the blood of a black-headed gull. These genes were then modified to reduce the virus's pathogenicity and combined with genes from a safe H1N1 strain grown in the laboratory. The result was a hybrid virus capable of multiplying efficiently in chicken embryos, an important feature for large-scale vaccine production.

In vaccination experiments, chickens that received two doses of the new vaccine, administered 14 days apart, developed antibody levels ten times higher than the minimum threshold considered necessary for protection against H5N1. These results demonstrate a high immunogenicity of the new vaccine variant, according to data presented by the Russian Science Foundation, suggesting significant potential for its use in combating the spread of the virus.