No one whose opinion deserves a moment's consideration can doubt that most of the great positive evils of the world are in themselves removable, and will, if human affairs continue to improve, be in the end reduced to narrow limits. J. S. Mill, Utilitarianism, II, 1863 Mill was not writing about herpesviruses, but had he known them as we do, he would have included them among the great positive evils of the world. They cause disease and premature death, and are very costly to our society. There is no loftier aim than to cure or prevent human infections with these viruses. The objective of much of the current research on herpesviruses is directed toward an understanding of the molecular mechanisms involved in initiation of infection, establish­ ment and termination of latent state, virus multiplication, and the destruction of cells which ultimately is the basis of the diseases caused by these viruses. At no time during the past 80 years, since members of the herpesvirus family were first discovered, has there been so much progress in our understanding of the biology of these viruses as in the past few years. Along with the development of a greater understanding of the molecular biol­ ogy of the well-known herpesviruses we have witnessed the isolation of new human herpes­ viruses.