© MEHAU KULYK/SCIENCE PHOTO LIBRARY/CORBIS
When it comes to viruses, those that transiently infect their hosts and cause the most damage get a lot of attention. Hollywood makes movies about Ebola, or about fictional viruses that resemble souped-up versions of the 1918 pandemic flu. Another viral world—one much closer to home—rarely enters the collective consciousness: the human virome.
A diverse, abundant, and underappreciated viral community exists on and within us, from our skin to our eyes, blood, brain, and other organs—even within our own genomes.1 Unlike marauding Ebola-like viruses, these viruses establish a balanced coexistence that can persist for a host’s entire lifetime. This coexistence involves careful control of the viral life cycle: whereas Ebola virus infection is flashy, persistent infection is elegant. (See illustration.)
Among other challenges, persistent viruses must effectively subvert the host immune response. To accomplish this, these viruses control both the timing and amount of viral replication. Such nuanced infectious cycles involve carefully choreographed ...
