- 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.