In this difficult period of the SARS-CoV-2 (and its variants) infection responsible for Covid-19 diseases, the importance of scientific works and reviews dealing with these viruses has never been more essential and vital. Reports as of 20th April 2021 indicate over 141 million cases of SARS-CoV-2 infection worldwide (with over 3 million deaths recorded). This volume brings together essential data regarding prevention (vaccination), detection, and various approaches (chemotherapeutic drugs and antibodies) to the potential treatment of coronavirus infections. It presents six chapters concerning the following topics: (1) the resistance to the spread of SARS-CoV-2 and related Covid-19 diseases within a population based on the pre-existing immunity of a high proportion of individuals as a result infection or previous vaccination (2) the impact of the Covid-19 pandemic for the South Asian Association for Regional Cooperation (SAARC) region, comprising the Bangladesh, Bhutan, Maldives, Nepal, Pakistan, Sri Lanka, India, and Afghanistan (3) the effect of candidate drugs chloroquine and hydroxychloroquine on QT interval in infected patients with Covid-19 diseases (4) the antiviral potential of herbal-based immunomodulators (5) the humoral immune response in humans based on anti-SARS-CoV-2 antibodies to treat Covid-19 diseases (6) the various methods and strategies for diagnosing SARS-CoV-2 (and its variants) infection in hosts/humans. This compilation should prove to be a tool of crucial importance for researchers around the world working on research revolving around coronaviruses, as well as for clinicians confronted by a growing number of patients with COVID-19.