RUSSIAN SCIENTISTS DEVELOP NEW H5N1 VACCINE STRAIN

ST. PETERSBURG, Jan 21 (Bernama-Xinhua) -- Russian scientists have created a new vaccine strain as a basis for developing vaccines against the highly pathogenic H5N1 avian influenza virus, the Russian Science Foundation announced on Tuesday, reported Xinhua.

The new strain precisely matches currently circulating variants and targets contemporary H5N1 viruses while remaining safe for both animals and humans, the foundation said on its website.

It added that the research was carried out by scientists from the St. Petersburg State University of Veterinary Medicine and the A.A. Smorodintsev Research Institute of Influenza.

Highly pathogenic H5N1 continues to circulate worldwide, causing mass mortality among domestic and wild birds and significant economic losses.

Its high variability and ability to cross species barriers reduce the effectiveness of older vaccines that do not match circulating strains, it said further.

The scientists used reverse genetics to engineer the virus.

Genes encoding hemagglutinin and neuraminidase from an H5N1 virus isolated from a black-headed gull in 2023 were modified to reduce pathogenicity and combined with genes from a safe laboratory H1N1 strain, resulting in a hybrid virus that replicates efficiently in chicken embryos.

In vaccination trials, chicks given two doses 14 days apart developed antibody levels against H5N1 that were ten times higher than the minimum required for protection, demonstrating the high immunogenicity of the new vaccine strain, the Russian Science Foundation said.

--BERNAMA-XINHUA