Oleg Kiselev, director of the Russian Academy of Sciences' Influenza Institute, said the vaccine was currently undergoing clinical tests. He said no human cases had been registered in the country so far, but that it was important to release the vaccine before spring, when the virus might return with migratory birds.
Kiselev said most viruses mutated to create variation and sidestep immune defenses. He said the structure of a virus and its properties could mutate dramatically as a result of recombination and that current forms of bird flu, incapable of spreading from person to person, could eventually evolve into strains transmittable by human-to-human contact.
Demographic changes in the years ahead will lead to the emergence of new pathogenic strains, the scientist warned. He said the risk is highest in densely populated areas, such as Southeast Asia, where people and animals live closely together, creating ripe conditions for the spread of viruses that can jump species.