The second edition of Virology is an accessible introduction designed to enable students to understand the principles of virus structure, replication and genetics. The aim of this book is to help the reader appreciate the relevance of virology in the modern world, including the fields of vaccines, anti-viral drugs and cancer. There is also a chapter on prions. The second edition has been extensively revised and updated to reflect the many developments in virology and offers deeper insights into the subject. Newly-discovered viruses are discussed and there is an additional chapter on the influenza virus.