A recent study has shed light on the potential of certain virus lineages to cause a global pandemic, prompting the need for continuous monitoring of viruses related to known human pathogens. The research highlights the significance of preparing for future pandemics by informing vaccine and diagnostic development and refining surveillance efforts to focus on the most threatening RNA viruses.

Understanding the ancestry of virus families may assist researchers in pinpointing which variants possess the potential to become Disease X, the elusive pathogen responsible for the next worldwide pandemic. The study has identified 70 virus lineages – groups of related viruses – that pose the biggest risk, while viruses from other genetic backgrounds are unlikely to cause a high number of infections in humans.

The findings are expected to support ongoing efforts to monitor and prepare for future pandemics, including guiding vaccine and diagnostic development. Disease X is a generic term used by the World Health Organization to represent a hypothetical, unidentified pathogen that could pose a significant threat to people.

RNA viruses, which carry their genetic information as RNA, have been responsible for most recent epidemics, including the common cold, Covid-19, and measles. Monitoring RNA viruses in animal populations could help identify those most likely to emerge and spread rapidly in humans, despite the significant challenge and expense posed by the huge number of circulating RNA viruses.

The research team, led by the University of Edinburgh, traced the lineage of 743 distinct RNA virus species to track their evolution, including all species currently known to infect humans. By comparing the development of strictly zoonotic viruses with human-transmissible viruses, the findings revealed the potential of viruses that can spread within human populations.