Several members of the MMI department focus their research on viruses, small infectious agents that can replicate only inside a host cell. A wide variety of viruses exist, infecting almost every type of living organism. Some viruses that infect humans may cause common illnesses such as the common cold, flu, chicken pox and cold sores. Others may cause serious diseases such as AIDS and SARS. Projects in the department utilize several different viruses such as HIV (Human Immunodeficiency Virus) to gain insight into the assembly and structure of the virus particle or genetically alter HSV (Herpes Simplex Virus) to study its ability to replicate within the host cell and be transferred to another cell. CMV (Cytomegalovirus) is used for studies involving the host’s immune response to viral infections as well as vaccine development. These various approaches to studying viruses give us a better understanding of the complicated interactions between host and infectious agent.