After looking at chickens’ genome to see what makes them susceptible to avian flu, researchers at the University of Edinburgh have used the CRISPR gene editing technique to create chickens better able to resist the infection.

The group found a gene humans lack but chickens have and that gene makes them vulnerable to the disease. By introducing mutations into that single gene, they were able to make flu-resistant birds.

To test the alteration, they droppered avian flu virus into the nostrils of 20 two-week-old chicks, 10 of which had the edited gene. All of the unaltered birds got sick; only one of the edited birds did. That one was unable to transmit the infection to the other edited chicks.

When the Edinburgh researchers gave edited chicks a dose of flu 1,000 times stronger than the original, all became sick.

However, their illnesses developed more slowly and ultimately became less severe than in their wild counterparts. Also, once again, the edited birds were less able to infect others.

Not everyone welcomes this advance.

Viruses are notoriously able to mutate to avoid the immune system’s defenses. If the avian flu virus mutates to avoid the new gene edits, it will be more likely to jump from birds to people, some virologists have warned.

Making additional edits to make chickens even more resistant to avian flu are possible. However, those changes would likely harm the chickens’ physical development and fertility, the Edinburgh scientists said. 

TRENDPOST: The Edinburgh experiment is useful as a “proof of concept” that resistance to certain illnesses can be built into our genes. However, it also proves that messing with a genome is like pulling a thread on a sweater: what began as a simple step turns into a complex problem.

Scientists will continue to edit genomes, including our own, to build resistance to some illnesses and completely eliminate other conditions. 

However, that will be a slow, decades-long process as each step is tested thoroughly and rigorously before regulators will allow it to be built into the chain of human evolution.