H5N1, otherwise known as Avian or Bird Flu, has been around for a long time. Mostly, the virus has been passed among wild birds, but there have also been sporadic outbreaks in poultry flocks. Now, the virus has spread to dairy cattle and, in at least two cases, from cattle to people. This has experts in pandemic prevention on high alert. Dairy workers come in close contact with cattle, raising concerns that the virus could mutate in such a way that it can be transmitted not only from animals to people but also from human to human.

Joining me to discuss the risk that H5N1 could become a virus capable of human-to-human transmission, and what can be done to prevent that, is Robyn Alders. She is an honorary professor with the Development Policy Center at the Australian National University and a member of the Lancet Commission on the Prevention of Viral Spillover. We begin by discussing the history of H5N1 before delving into the current outbreak among dairy herds. Alders also explains why addressing the root cause of these outbreaks requires a fundamental shift in how we approach food systems.