- Scientists discover two to three new human viruses annually, a trend stable since the 1960s.
- Most new viruses are low-risk, but some, like HIV-1 and SARS-CoV-2, have led to pandemics killing millions.
- The University of Edinburgh team uses historical data to assess pandemic potential of newly discovered viruses.
- RNA viruses are the main pandemic culprits; 239 infect humans, with spread between people key for pandemic risk.
- Two-thirds of listed viruses are zoonotic, unlikely to spread human-to-human, though evolution could change this.
- Viruses already capable of human-to-human spread pose a greater threat, as seen with measles and SARS-CoV-2 variants.
- Some viruses cause limited outbreaks due to low R numbers, but urbanization can increase transmissibility (e.g., Ebola in 2014).
- The outbreak virus list predicts public health emergencies, including Ebola, Zika, and mpox, which caused major epidemics.
- Rare viruses like Andes hantavirus and Bundibugyo ebolavirus are becoming more familiar due to recent outbreaks.
- Future pandemic viruses (disease X) may resemble SARS-CoV-2: highly transmissible, related to human-spread viruses, but emerging from animals.
- Early detection of new viruses is crucial to prevent pandemics, as delays allowed COVID and others to gain a head start.