Pathogenesis

Jonathan Kennedy – a reader in politics and global health at Queen Mary University of London’s Centre for Public Health and Policy – details how bacteria and viruses have served as the driving force behind migrations, conquests, and the rise and fall of entire societies.

Microorganisms

Microorganisms make up the vast majority of Earth’s life forms. Viruses are just as ubiquitous and even more abundant than bacteria. They keep bacteria under control by infecting and killing them.