COVID-19 is a new virus spreading worldwide that can cause mild to severe illness, multi-organ failure, and even death. Injectable antiviral Remdesivir is effective in treating patients with moderate-to-severe COVID-19. Biomarkers linked to clinical outcomes have been found for COVID-19, although only a few antiviral therapies have been studied. This study aimed to assess how Remdesivir affects several biomarkers in patients with COVID-19 and how those changes impact the severity of the illness. According to Chinese care guidelines for COVID-19, 80 patients with COVID-19 were separated into two groups: group 1 did not receive Remdesivir (RDV) medication and Group 2 received it after 5 days. Injectable antiviral Remdesivir has recently been tested in high-risk, individuals with confirmed SARS-CoV-2 infection who were not hospitalized, and it successfully delayed the onset of the illness. From February 2022 to October 2023, blood samples were taken from study participants to evaluate ferritin, Lactate Dehydrogenase (LDH), and C-reactive protein. The results of this investigation showed that various COVID-19 severity biomarkers, including ferritin, C-reactive protein, and lactate dehydrogenase, may improve more quickly with RDV treatment. These biomarkers are linked to better clinical outcomes during infection. These discoveries enhance the understanding of the COVID-19 antiviral treatment’s function. In conclusion, there is a clear association between the levels of biomarkers before and after Remdesivir treatment in COVID-19 cases ranging from moderate to severe. This suggests that the COVID-19 infection might lead to the elevation of several biomarkers.