A CRISPR-based therapeutic designed to treat highly pathogenic avian influenza (HPAI) could become a new tool for producers facing increasingly frequent and costly outbreaks.
"The ultimate goal is to have something that you can give a farmer when they have an infected animal or infected bird and save the farm," said Douglas Gladue, vice president of Veterinary Pharmaceutical Development at Seek Labs. “The projected final product would ideally have a profile that could help prevent spread on the farm, as well as treat and save birds.”
Seek Labs, working in collaboration with the Canadian Food Inspection Agency, has received funding from the Highly Pathogenic Avian Influenza Poultry Innovation Grand Challenge Award to design and test the therapeutic specifically for HPAI.
If successful, the treatment could one day allow producers to intervene when a flock tests positive, rather than defaulting immediately to total depopulation. Previously published research showed positive results for a similar therapeutic approach against African swine fever in swine.
Multiplexing against flu mutations
HPAI can mutate quickly, making it difficult to develop a single treatment against the virus.
The new approach uses the gene editing tool CRISPR to cleave the flu genome at multiple sites simultaneously, also known as multiplexing. This targets regions of the genome that mutate less frequently, making it significantly harder for the virus to evolve its way around treatment.
In other words, with a multiplexed CRISPR approach, the virus would need to accumulate changes across several genomic sites simultaneously to escape.
Because the approach targets specific nucleotide sequences rather than proteins, researchers can monitor changes in circulating flu strains through global surveillance data and adjust the therapeutic design before resistance becomes a problem.
“By doing constant monitoring and looking at the different sequences of the flu, you could, in theory, be prepared for the next year a lot easier,” he added.
Delivery method remains an open question. Aerosol and oral administration are considered the most practical options for commercial poultry housing, but Gladue acknowledged the company must first confirm efficacy before tackling that challenge.
The current development roadmap begins with designing a flu-specific therapeutic, followed by cell culture testing and then live animal trials in chickens, with plans to expand to additional poultry species.
Later-stage studies would simulate farm outbreak conditions to evaluate whether treatment can also limit spread within a flock.
To learn more about HPAI cases in commercial poultry flocks in the United States, Mexico and Canada, see an interactive map on WATTPoultry.com.
View our continuing coverage of the global avian influenza situation.
