Rearing virus-resistant birds could benefit humans too, say scientists, and Covid may have made us more open to the controversial technology
Diseases such as avian flu trigger the culling of millions of birds each year. But that need not be the case for much longer.
Vaccines are one preventive strategy employed in some countries, but they do not stop birds from being infected, getting mild versions of the disease and transmitting it to healthy chickens. In fact, this imperfect shield can make things worse, incentivising the virus to mutate to evade the vaccine.