Unraveling SARS-CoV-2: A comprehensive review of origin, structure and therapeutic targets

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in late 2019 triggered the global COVID-19 pandemic, presenting an unprecedented public health challenge. This review synthesizes critical aspects of SARS-CoV-2, beginning with its origin, which genomic analyses trace to bat coronaviruses like RaTG13, though the exact transmission pathway to humans remains debated. The virus possesses a large ~30,000-nucleotide RNA genome encoding structural, non-structural, and accessory proteins that facilitate replication and pathogenesis. Key structural proteins include the Spike (S) protein, which mediates host cell entry via the ACE2 receptor. The review details the virus's epidemiological characteristics and the emergence of Variants of Concern (VOCs) such as Delta and Omicron, driven by viral evolution and selective pressures. A significant portion is dedicated to the functions of viral proteins, highlighting their roles in viral replication, immune evasion, and contributing to severe disease. Furthermore, the article surveys diagnostic methodologies, emphasizing molecular techniques like RT-PCR as the gold standard, and explores emerging biosensor technologies. Finally, it outlines therapeutic strategies, cataloguing antiviral drugs that target essential viral components, including the main protease and RNA-dependent RNA polymerase. This comprehensive overview underscores the multifaceted understanding required to combat SARS-CoV-2 through diagnostics, therapeutics, and public health measures.