ISSUE 9

Abstract:
The emergence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has resulted in a rapidly evolving global health challenge, with Coronavirus Disease 2019 (COVID-19) transitioning from an acute pandemic to a persistent public health concern. Continuous viral evolution has led to the emergence of multiple variants and sub lineages with altered transmissibility, immune evasion, and clinical characteristics. This review provides an updated overview of the evolving landscape of SARS-CoV-2 infection, encompassing epidemiology, viral pathogenesis, emerging variants, diagnostic advancements, vaccination, therapeutic strategies, and post-acute sequelae of COVID-19, commonly referred to as Long COVID. Particular emphasis is placed on the molecular mechanisms underlying SARS-CoV-2 infection, including spike protein-mediated interaction with angiotensin-converting enzyme 2 (ACE2) and host proteases such as transmembrane serine protease 2 (TMPRSS2), as well as the dysregulated immune responses associated with severe disease and organ injury. The review further discusses major SARS-CoV-2 variants, including Alpha, Beta, Gamma, Delta, and Omicron, along with subsequent Omicron sublineages and their implications for immune escape and disease transmission. Advances in molecular, antigen-based, and serological diagnostic approaches, including multiplex RT-PCR and immunoassay-based methods, are also examined. In addition, the impact of vaccination, booster strategies, breakthrough infections, and global disparities in vaccine access is discussed. Emerging evidence concerning Long COVID, including persistent multisystem manifestations and proposed mechanisms such as immune dysregulation, endothelial dysfunction, microclot formation, and mitochondrial abnormalities, is highlighted. Finally, current therapeutic and preventive approaches are reviewed, emphasizing the need for continued surveillance, improved diagnostic strategies, vaccination, evidence-based treatment, and integrated public health measures. Collectively, this review highlights the continuing evolution of SARS-CoV-2 and the importance of adaptive strategies for reducing the long-term clinical and public health burden of COVID-19.

Keywords: 

 SARS-CoV-2; COVID-19; Emerging Variants; Long COVID; Diagnostic and Therapeutic Strategies