New Virus Catalog Identifies High-Risk Pathogens

Scientists at the University of Edinburgh have developed a new catalog that aims to identify which viruses pose the greatest threat of causing future public health emergencies. In a typical year, researchers discover two to three novel viruses infecting humans, a number that has remained relatively steady since the 1960s. While most of these discoveries garner little attention, some, like HIV-1 in 1983 and SARS-CoV-2 in 2020, have led to devastating pandemics, resulting in tens of millions of deaths.

The new catalog focuses on RNA viruses, which have been responsible for recent major pandemics. Thousands of RNA virus species have been identified, with potentially millions existing, yet only 239 are known to infect humans. The research team analyzed historical data and virus characteristics to pinpoint the riskiest among these. Key indicators for pandemic potential include the type and severity of disease caused, but crucially, the ability of the virus to spread between people.

Transmission routes can vary, including physical contact, airborne particles, exposure to bodily fluids, or vector bites from insects like mosquitoes or ticks. The catalog indicates that for approximately two-thirds of the listed viruses, human-to-human transmission is highly unlikely. These are primarily zoonotic viruses, meaning they are typically transmitted from animals to humans, with rabies being a notable example. This classification offers some reassurance regarding their immediate pandemic potential.

However, the catalog also addresses the significant concern that zoonotic viruses can evolve and acquire the ability to spread efficiently among humans. This evolutionary potential is the underlying reason for the intense scientific scrutiny surrounding viruses like bird flu. The research acknowledges that while documented instances of RNA viruses evolving widespread human-to-human transmission are rare, the possibility remains a critical focus for global health surveillance and preparedness efforts.