THE race to contain the Covid-19 pandemic will not be around forever. The world is doing its utmost to stop the deadly virus. However, even if the number of infections and deaths reach a full stop, there can be no sighs of relief. New viruses will come and infect people.

Nearly all new infectious diseases that scientists know about today originate in animals and so will the emerging diseases of tomorrow. The human immunodeficiency virus (HIV) began in chimpanzees, severe acute respiratory syndrome (SARS) in bats and influenza in aquatic birds. At some point, the animal pathogens jump the species barrier to humans, which experts call spillovers.