Gene-edited pigs, resistant to a deadly virus, could soon be found on farms across the US. This breakthrough in genetic engineering aims to combat porcine reproductive and respiratory syndrome (PRRS), a costly and often fatal disease affecting millions of pigs worldwide. With the potential to save farmers billions of dollars annually, this innovation has sparked both excitement and controversy.
PRRS poses a significant challenge for pig farmers, costing them up to $2.7 billion each year. Current vaccines offer limited effectiveness, and treating infected pigs with antibiotics can lead to the development of resistant bacterial diseases. In response, Genus, a leading breeding company, has turned to CRISPR gene editing technology to create pigs that are immune to PRRS. By removing a specific protein called CD163, researchers have rendered the pigs incapable of contracting the virus.
However, achieving this feat has been no easy task. Only a small percentage of piglets bred by Genus possess the desired gene, and even then, the modification is not uniform across all body cells. This variability, known as mosaicism, presents a challenge in ensuring consistent immunity. Additionally, some gene-edited pigs may exhibit unintended changes in their genome, raising concerns about unintended consequences.
Despite these challenges, Genus has made significant progress and anticipates receiving regulatory approval from the US Food and Drug Administration to start selling these pigs as early as next year. Similar approvals are also being sought in other countries, including China and Mexico, major importers of US pork.
While the potential benefits of PRRS-resistant pigs are clear, critics argue that the focus should be on addressing the root causes of disease in livestock rather than genetically modifying animals. Factory farming practices, characterized by overcrowded and unsanitary conditions, contribute to the emergence of diseases and the overuse of antibiotics. Animal rights advocates emphasize the importance of improving living conditions for farm animals to prevent the spread of diseases, rather than relying solely on genetic engineering solutions.
The development of gene-edited pigs resistant to PRRS represents a significant advancement in agricultural technology. However, ethical and practical considerations surrounding animal welfare and factory farming practices highlight the need for a comprehensive approach to address the challenges facing the livestock industry.