This book aims to serve as a sourcebook for molecular virology. This text deals with diverse features of molecular virology. The book analyses HIV-1 virus and its latency and how these twin phenomena have remained a dispute to abolition. Features concerning the molecular evolution of hepatitis viruses, including their genetic variety, with suggestions for vaccine improvement are discussed within this book. Metabolic diseases that are a result of the hepatitis C virus are analyzed. This book even deals with influenza C virus and the functions of viral vectors in beneficial study. Avian influenza and the healing prospective of belladonna-200 against Japanese encephalitis virus disease are, also, researched within this book. Baculoviruses and its relations with polydnaviruses are thoroughly revised in this text. This book intends to help students and experts in gaining more knowledge regarding the above stated topics.