The ongoing goal in farming has been to produce animals capable of resisting diseases that currently threaten the human food supply. That goal is spurred by the increase in disease events and animal vulnerability associated with climate change. So it is that news of the world’s first successful superpigs has met with cheers from swine producers worldwide. The pigs are genetically modified to be resistant to the incurable and fatal blue-ear disease.
Blue-ear disease is formally known as Porcine Reproductive and Respiratory Syndrome (PRRS). The virus attacks the pig’s immune system, presents largely as a respiratory infection, and is usually fatal. There is no cure.
“PRRS is the most economically significant disease to affect US swine production since the eradication of classical swine fever (CSF),” according to an Iowa State University College of Veterinary Medicine document. “Although reported initially in only a few countries in the late 1980s, PRRS now occurs worldwide in most major swine-raising countries.”
It’s not a disease farmers take lightly, in other words. But it’s one they can do little about.
“There is no specific treatment for PRRS. Broad-spectrum antibiotics may be useful in controlling secondary infections. Anti-inflammatory products (e.g. aspirin) are commonly administered during acute disease,” according to the Iowa State document.
So it’s no small thing that researchers have produced the world’s first genetically modified pigs that are highly resistant to the ailment.
Researchers at Genus, a British animal genetics company, worked with U.S. scientists at the University of Missouri to do the complex gene editing needed to eradicate the protein that enables PRRS to spread inside the pig’s body.
"Once inside the pigs, PRRS needs some help to spread; it gets that help from a protein called CD163," Randall Prather, professor of animal sciences in the university's College of Agriculture, Food and Natural Resources, explained in a news release.
"We were able to breed a litter of pigs that do not produce this protein, and as a result, the virus doesn't spread. When we exposed the pigs to PRRS, they did not get sick and continued to gain weight normally."
It’s important to pause a moment and reflect on the importance of what was done here. These scientists effectively immunized the pigs but they did not otherwise alter the pigs’ nature or biological structure. That is an important distinction that many critics of GMO foods do not seem to grasp.