Scientists use CRISPR to make chicken resistant to bird flu as many countries prepare for the major outbreak of bird flu known as avian influenza due to seasonal migration and climate change, Scientists have announced that breeding chickens that can resist the virus- with the help of CRISPR genome editing technology- is proving to be a promising tool in the fight against viral diseases.
Building on their findings, the ingenious chicken team used genome editing techniques to alter the ANP32A protein in chicken cells which the bird flu uses to replicate.
How CRISPR Gene Editing Can Combat Bird Flu
The scientists are from the University of Edinburgh, Imperial College London, and Pirbright Institute. Though the result was fascinating, one genetic change will not be enough. When chickens were genetically modified to receive a normal dose of H9N2 bird flu, nine out of ten birds remained healthy and non-spread to other chickens.
Then they found that the genetically modified bird had been artificially dosed with the virus, with five out of ten becoming infected, which they said was far less than unmodified chickens exposed to the same dose. Genome editing also made it possible to limit the spread to 1 in 4 non-GM chickens in the same incubator, without transmission to GM birds.
The team said that modifying one of the ANP32A protein genes was not robust enough to be applied to chicken production, and they are investigating the possibility of using laboratory-grown chicken cells to modify two other proteins that they believe also play a role in the formation.
A virus leak led researchers of one of the studies to say in a paper that bird flu remains a threat, but vaccination poses several challenges in terms of cost.
Genome editing offers a promising route to permanent disease resistance that can be passed down from generation to generation, protecting chickens and reducing risks to humans and wild birds. This study shows that interrupting the spread of Avian influenza in chicken require several simultaneous genetic changes.
Although more needs to be done to get the perfect combination of genetic modifications to apply this approach in the field, the results have taught us a lot about how the bird flu virus works inside an infected cell, and how it shows its replication, pros and cons of vaccination and new European regulations.
Vaccination of chickens in part of Asia has been used as a military strategy, particularly by China, and was first widespread in Europe, with France recently introducing vaccination of ducks. The significant disadvantage of vaccination is that sometimes, vaccinated birds can still get the virus without showing any Symptoms, which can mask the spread of the disease.
Vaccination concerns could lead to restrictions on imports, and in late September, the US Department of Agriculture ( USDA) announced restrictions on poultry from France and its trading partners due to the risk of importing highly pathogenic influenza into the US.
In the same vein, the European Food Safety Authority (EFSA) on avian influenza vaccination in chickens, describes available vaccines and provides information on vaccination strategies.
The EFSA said there is only one bird flu vaccine approved for chickens in the European Union and it can not supply other vaccines. He added that few vaccines have been tested on other than chickens.
Preventive vaccination is the best strategy to reduce the number and duration of outbreaks and appears to be a useful tool in high-risk areas.
In the event of an epidemic, it recommends vaccination within a 3km radius around the epicenter of the epidemic and areas with the highest risk. The group stressed that vaccination should be used in conjunction with other Prevention and control measures such as monitoring, early detection, and biosecurity.