Scientists have achieved a breakthrough by creating gene-edited chickens with partial resistance to bird flu, raising the possibility of eventually blocking the virus completely in these birds.
While these genetically modified chickens are not entirely immune, the researchers believe that further modifications to their DNA could yield fully resistant chickens within the next three years.
In the study, three genes that were crucial for the bird flu, formally known as avian influenza, to reproduce in chickens were identified. By using a gene-editing technique, scientists made two small changes to one of these genes. As a result, the chickens showed increased resistance to bird flu without any side effects. However, it’s worth noting that not all of the birds were fully immune; half of the chickens infected with a high dose of the virus still developed an infection.
Although achieving any level of resistance to bird flu is significant, complete immunity is the ultimate goal for practical use. Partial resistance can potentially lead to the virus mutating to become more dangerous to humans if widely used.
Yet, Professor Mike McGrew of the Roslin Institute expressed confidence in achieving full immunity. He explained that experiments conducted in test tubes indicated that modifying all three genes could produce birds that are fully resistant to bird flu. These gene edits stopped the flu virus from replicating altogether without harming the birds.
Gene editing entails making precise changes to DNA to alter the function of a gene, in this case, disabling the genes that assist bird flu without any harm to the birds themselves.
The researchers are now focused on identifying the additional genetic changes required for creating gene-edited chickens in the next phase of their research.
Bird flu remains a significant global threat, affecting both farmed and wild bird populations. For example, the recent outbreak of H5N1 bird flu in the UK has led to substantial seabird population declines and more than £100 million in losses for the poultry industry.
However, it’s important to note that efforts to manage bird flu must not inadvertently lead to poor animal conditions on farms. Critics, such as Peter Stevenson of Compassion in World Farming (CIWF), argue that tackling diseases with gene editing should not enable the continued crowded and stressful conditions in industrial poultry production, which are factors contributing to highly pathogenic bird flu.
CIWF has supported gene editing as a means to prevent the euthanizing of billions of unwanted male chicks at birth in the egg production industry but insists that the technology should be used primarily to reduce animal suffering.
Around the world, research is ongoing to develop gene-edited animals that are resistant to diseases and more productive. While legislation allowing the commercial use of gene-edited food has been passed in some countries, including the UK, further parliamentary votes may be needed to ensure animal welfare as these technologies are implemented.
The study has been published in the journal Nature Communications.