What pathogen could trigger the next pandemic? How scientists are preparing for ‘disease X’

Before the COVID pandemic, the World Health Organisation (WHO) had made a list of priority infectious diseases. These were felt to pose a threat to international public health, but where research was still needed to improve their surveillance and diagnosis. In 2018, “disease X” was included, which signified that a pathogen previously not on our radar could cause a pandemic. While it’s one thing to acknowledge the limits to our knowledge of the microbial soup we live in, more recent attention has focused on how we might systematically approach future pandemic risks.