A Comprehensive Review on COVID-19: Virology, Molecular Diagnosis and Exploration of Mesenchymal Stem Cells (MSCs) for Its Treatment

Background: COVID-19, instigated by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) appeared in 2019 and has since caused a universal health crisis. The virus’s pathogenicity is primarily due to its unique structure, mode of transmission and capacity to evade the host immune response. While traditional treatment and diagnostic strategies have evolved, the elevated morbidity and mortality linked with severe infections necessitate advanced approaches. Among these, Mesenchymal Stem Cells (MSCs) have gained attention as a potential therapeutic strategy owing to their regenerative and immunomodulatory capabilities. Methods and Findings This review explores SARS-CoV-2 virology, transmission mechanisms, immune response and the viral life cycle. It summarizes current molecular diagnostic methods-RT-PCR, RT-LAMP, CRISPR, ELISA, gene sequencing, biosensors and imaging techniques-and discusses their relative advantages and limitations. For treatment, various antivirals, monoclonal antibodies and glucocorticoids are examined. The paper extensively discusses MSCs sourced from bone marrow, adipose tissue and umbilical cord, which have shown promising results in managing severe COVID-19 symptoms. MSCs mitigate cytokine storms, promote lung repair and reduce inflammatory markers. Clinical trials have reported improved oxygen saturation, reduced ICU stays and lower mortality in critically ill patients receiving MSCs therapy. Conclusion: Mesenchymal Stem Cells (MSCs) offer promise in COVID-19 treatment due to their immune modulation and tissue repair abilities and their resistance to SARS-CoV-2. However, issues like protocol variability, high cost and unknown long-term safety remain. Future work should refine dosage, delivery and explore synergies with gene editing and extracellular vesicles. Large trials and AI-driven frameworks are vital for mainstream clinical use.