Gene Editing to Protect Pigs from PRRS

Livestock | March 2026

Written by:

Jennifer Ryan has been writing about veterinary topics for nearly 20 years. She has a master’s degree in journalism, a bachelor’s degree in agricultural communications and decades of experience caring for both livestock and pets.

One of the costliest diseases affecting pigs may soon be a distant memory — and it’s set to reshape the global pork supply. In April 2025, the U.S. Food and Drug Administration approved the use of a gene-editing technology that creates pigs resistant to porcine reproductive and respiratory syndrome (PRRS).

Since emerging in U.S. swine herds in the mid-1980s, PRRS has become one of the most economically devastating diseases in modern animal agriculture. PRRS is responsible for an estimated $1.2 billion loss per year in U.S. pork industry production, according to a recent analysis by Iowa State University.1

The analysis, led by researchers in Iowa State University’s College of Veterinary Medicine, determined that the rising economic impact is largely driven by a higher proportion of infected herds and ongoing productivity gaps between affected and unaffected farms — not simply changes in pork prices, input costs or herd size.

PRRS is a highly contagious viral disease that affects pigs, causing reproductive failure in breeding animals — including abortions, stillbirths and weak-born piglets — and respiratory illness in young pigs. The virus spreads through direct contact, contaminated equipment and transport, and even through the air under certain conditions. It mutates frequently, making control difficult and limiting the long-term effectiveness of vaccines. As a result, PRRS remains one of the most economically damaging diseases in global swine production.

PRRS-resistant pigs not yet for sale

The owner of this gene-editing technology, Pig Improvement Company (PIC), expects the new technology to launch in U.S. swine herds in 2027.

“PIC recognizes international trade is critical to pork producers’ viability, which is why we are working to secure approvals in additional key pork markets prior to commercializing in the U.S.,” said Perry Harms, DVM, global director of health assurance for PIC. “The PRRS-resistant pig is not currently for sale in the U.S. PIC foresees commercialization in early 2027.”

PIC partnered with researchers at the University of Missouri to identify a solution to the challenges of the PRRS virus. Using gene editing, researchers removed the binding site of the target protein, CD163.

“Without that specific protein, the PRRS virus cannot bind to a pig’s DNA, making them resistant to the disease,” Harms explained. “Like humans inherit traits from their parents, the pig’s offspring will inherit the PRRS-resistant trait. Since the original edit was made in the founder population of pigs more than six years ago, PRRS-resistant pigs have since been bred through traditional breeding.”

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Robust protection

Peer-reviewed research has shown these pigs are resistant to multiple lineages of PRRS Type I and Type II strains, which
are the most prevalent. This will deliver built-in protection against the most troublesome strains currently challenging the U.S. pork industry.

“The PRRS-resistant pig has been 100% effective against virtually all strains tested, and it has been proven to be a robust tool in combatting PRRS compared to alternatives,” Harms noted.

Global economic impact

Jayson Lusk, Ph.D., Regents Professor of Agricultural Economics at Oklahoma State University, developed an economic model to gauge the worldwide impact of this gene-editing technology. It found significant increases in productivity that will be positive for adopting pork producers.

Funded by PIC, the model used pork production information, trade statistics, supply and demand elasticities, PRRS prevalence rates and productivity metrics by PRRS health status. The model then predicted changes in pork prices, production, trade and producer profits.

“A very large percentage of pigs have PRRS. If you can eliminate PRRS, there’s a pretty big boost in pigs per sow per year and the number of baby pigs that survive. The mortality rate amongst growing pigs improves tremendously,” he explained.

Assuming a 70% adoption rate over 12 years, the model’s baseline scenario found that:

  • The marginal cost of production declines
  • Prices fall
  • Pork production increases in adopting countries with around 11% in China and 7% in the U.S. and Canada
  • Pork production falls in nonadopting countries

One assumption Lusk made was no change in the costs of the genetics. Until the technology is commercialized, producers will not know the additional costs for including PRRS-resistant pigs in their herds.

“How big are the genetic costs to begin with? We did some back-of-the-envelope calculations and found that it’s less than a percent of the total cost of pork that gets producers to the packer level. Even if you double it, that’s not enough to do away with the gains calculated by eliminating PRRS,” he said.

The model’s baseline scenario assumes consumer demand for pork does not change. In the past, consumers have been hesitant to purchase some new food technologies. Lusk said he believes there is room to persuade consumers of the positive benefits of this technology, including reduced antibiotic use and improved animal welfare.

“The jury is still out, and the world has changed,” Lusk commented. “Retailers and food processors are deciding what hits the market. Now, we have a hundred gene-edited foods like non-browning produce. It’s not a one-off decision for them.”

Consumer acceptance

To gain adoption, the health and animal welfare benefits at the farm level must translate to continued trust from consumers. PIC has conducted four years of consumer research, surveying more than 5,000 people in eight countries. Consumers consistently showed a strong purchase likelihood for pork from gene-edited pigs.

“In the most recent survey, 94% of U.S. consumers indicated they are open to purchasing pork from gene-edited pigs,” Harms said. “The strongest acceptance is driven by reduced antibiotic use.”

PIC said the rollout of these genetics will be measured and allow the market — and consumers — to adjust.

“As with other traits, dissemination takes time,” Harms said. “Think of the introduction of the PRRS-resistant pig as a light dimmer switch, which gradually increases light in a room, versus an on-off switch. We anticipate the PRRS-resistant pig may take up to five years for the breed-up process, assuming normal replacement rates, and it will take several years to roll out the PRRS- resistant pig across key global pork markets.”

Key Points
  • PRRS has been present in U.S. swine herds since the mid-1980s.1
  • It causes respiratory distress in pigs of all ages and reproductive problems in breeding stock.1
  • The United States, Canada, Colombia, Brazil, Argentina and Dominican Republic have granted PIC the ability to use the gene-editing technology and treat the pigs like any other animals.

Reference:

  1. Roepke, D. (2024, July 30). Growing Losses from PRRS Cost Pork Producers $1.2 Billion Per Year, New Study Shows—Iowa State Research. Available at: research.iastate.edu/2024/07/30/growing-losses-from-prrs-cost-pork-producers-1-2-billion-per-year-new-study-shows.

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