Some unmet challenges in the immunology of viral infections.

Viral immunology is a rapidly evolving field. Major strides have been made in our understanding of innate and adaptive immune responses to viruses, largely based on highly reductionistic animal infection models, but more recently in humans, with validation that fundamental immunological concepts do in fact translate into clinical science well. From these studies there has emerged an appreciation of the enormous complexity of the immune response to viral infections as well as the diverse array of strategies developed by viruses to deal with immune detection. In this review, we highlight some of the major challenges we face in unraveling this complexity and summarize current efforts under way to improve the efficacy of viral vaccines.