virulence

A new essay explores how infectious diseases evolve their virulence, using a thought experiment about a lockdown among androids to isolate the trade-offs pathogens face between spreading and killing their hosts. The piece challenges the simple assumption that viruses always become milder over time, arguing instead that transmission and severity can pull in different directions. Readers are debating whether the classic 'virulence always declines' narrative about pandemics holds up.