The AIDS epidemic has popularized immune deficiency and has led to a rapid increase in the funding for research into the effect of viruses on immunity. There is now a real possibility of finding out whether some of the rare, so-called 'primary' immunodeficiency syndromes of children and adults, first described in the 1950s, may have a viral aetiology. Most of these syndromes have already been extensively reviewed more than once over the past 10 years, and their diagnosis and management is now included in most standard medical textbooks. In this volume, I have chosen to highlight what I...