Researchers claim to have found magic bullet against bird flu

Washington, Oct 20 (IANS) A single vaccine can protect humans, chickens and even cats against deadly flu pandemics, including the dreaded bird flu that has caused havoc in large parts of Asia, including India.

The vaccine also protects birds and mammals against different flu strains and can even be given to birds while they are still in their eggs, allowing the mass vaccination of wild birds.

The emergence of bird flu has posed a major challenge to scientists designing vaccines as it can infect a number of different animals, including birds, pets and people.

'The world is experiencing a pandemic of influenza in birds caused by an H5N1 virus. Although it has been restricted to Eurasia and some countries in Africa, there is a risk that this virus may spread worldwide,' said Daniel Perez, professor at the University of Maryland.

'The H5N1 virus also has an unusual expanded host range: not only have birds and humans been infected but also cats, which are usually resistant to influenza. To prepare for a pandemic, it would be ideal to have a vaccine that could be used in multiple animal species,' he added.

The study is scheduled to appear in the Journal of General Virology next month.

The researchers found that the central genes or 'backbone' of the H9N2 virus that infects guinea fowl can protect birds and mice against highly pathogenic strains of influenza.

They modified the virus to make it less pathogenic and then used it to vaccinate mice. Three weeks after being vaccinated, the mice were infected with the potentially lethal H1N1 virus - the same virus that caused the 1918 Spanish flu pandemic.

All the vaccinated mice survived with no signs of disease. Vaccinated mice also survived infection with the deadly H5N1 bird flu virus, again showing no signs of disease, according to a statement by the Society for General Microbiology.

'Our results show that the H9N2 backbone vaccine can be used to protect mice against two different, highly pathogenic strains of influenza. We chose genes from H9N2 influenza for the vaccine because the virus can infect many different animals, including chickens, mice and pigs,' said Perez.