14 DAY TRIAL // Researchers from the Universities of Cambridge and Edinburgh made a major breakthrough, that could prevent future bird flu epidemics – they created genetically modified chickens that if infected with the avian influenza virus, do not transmit it to other chickens with which they are in contact.
This genetic modification could stop bird flu outbreaks spreading within a group, and not only protect the health of domestic poultry, but also reduce the risk of bird flu epidemics triggering new flu virus epidemics in humans.
In order to obtain these chickens, the scientists introduced a new gene that created a small 'decoy' molecule simulating an important control element of the bird flu virus.
As a consequence, the replication mechanism of the virus falsely recognizes the molecule instead of the viral genome and this affects the replication cycle of the virus.
So the chickens infected with avian flu become sick, but they did not transmit the disease to other chickens kept in the same place with them, even if these birds were not genetically modified.
Dr Laurence Tiley, Senior Lecturer in Molecular Virology from the University of Cambridge, Department of Veterinary Medicine, explained that “the decoy mimics an essential part of the flu virus genome that is identical for all strains of influenza A.
“We expect the decoy to work against all strains of avian influenza and that the virus will find it difficult to evolve to escape the effects of the decoy.
“This is quite different from conventional flu vaccines, which need to be updated in the face of virus evolution as they tend only to protect against closely matching strains of virus and do not always prevent spread within a flock.”
Dr Tiley added that “chickens are potential bridging hosts that can enable new strains of flu to be transmitted to humans.
“Preventing virus transmission in chickens should reduce the economic impact of the disease and reduce the risk posed to people exposed to the infected birds.
“The genetic modification we describe is a significant first step along the path to developing chickens that are completely resistant to avian flu.
“These particular birds are only intended for research purposes, not for consumption.”
“Infectious diseases of livestock represent a significant threat to global food security and the potential of pathogens, such as bird flu, to jump to humans and become pandemic has been identified by the Government as a top level national security risk,” said Professor Douglas Kell, BBSRC Chief Executive.
“The BBSRC funds world-class research to help to protect the UK from such eventualities and the present approach provides a very exciting example of novel approaches to producing disease-resistant poultry,” he added.
Professor Helen Sang, from The Roslin Institute at the University of Edinburgh, said that “the results achieved in this study are very encouraging.
“Using genetic modification to introduce genetic changes that cannot be achieved by animal breeding demonstrates the potential of GM to improve animal welfare in the poultry industry.
“This work could also form the basis for improving economic and food security in many regions of the world where bird flu is a significant problem.”
The study was funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and is published in today's (Friday, 14 January) issue of the journal Science.