Virology is a fascinating and rapidly developing subject, and is worthy of study purely because viruses are interesting! There is a continuant need for trained virologists, and it is hoped that this book will play a small role to fulfil this need. This book is specially prepared to meet the demands on Zoology, Microbiology and Biotechnology UG and PG students of various Universities, it brings out the detailed information on introduction, history, classification, architecture, replication, pathogenesis, genetics, immunology, viral host interaction, bacteriophages, plant viruses, animal viruses, interferons, antiviral drugs, prions and viroids, virus genomes, vaccination, diagnostic methods and infection control measures.