Advances in technologies and enhanced surveillance have facilitated the monitoring of virus evolution, transmission dynamics, and pathogenesis. Coupled with the experiences of the COVID-19 pandemic, we have a better understanding of the interconnectedness of human, animal, and environmental health and the impact of viruses on society and the economy. Viruses: Molecular Biology, Host Interactions, and Applications to Biotechnology, Second Edition provides an update on recent developments, lessons learned, and perspectives on fundamental aspects of virology. Fully updated and revised, the Second Edition includes coverage on the history of viruses, their structure, the organization of their genomes, and strategies in replication and expression. The book emphasizes the diversity and versatility of viruses, how they cause disease, and how their human, animal, and plant hosts react to these diseases. It also explores the beneficial aspects of viruses and how they can be utilized as tools and targets for biotechnological application. This edition is likely to appeal to a wide audience, including academics, researchers, and students studying the molecular biology and applications of viruses.