Virology comprises the comprehensive study of viruses, which are infectious agents responsible for a spectrum of diseases. It probes into the mechanisms by which viruses invade host cells, replicate their genetic material, and disseminate within organisms. This discipline is crucial in explaining the molecular interactions that support viral infections and pathogenesis. Pathogenesis refers to the complicated process by which diseases reveal and progress within the host organism. In the context of viral infections, pathogenesis involves understanding the mechanisms by which viruses enter host cells, hijack cellular machinery for replication and induce cellular damage or immune responses. Different viruses exhibit varying pathogenic profiles, targeting specific tissues or organs and bring out characteristic symptoms such as fever, respiratory distress or systemic ailment. Comprehending virology and pathogenesis is foremost for developing therapeutic strategies and preventive measures, including vaccines, aimed at reducing viral diseases and safeguarding public health. This book unravels the recent studies in the field of immunology. It presents research and studies performed by experts across the globe. Scientists and students actively engaged in this field will find this book full of crucial and unexplored concepts.