Abstract: Microbes and Infectious Diseases 2021; Article In Press, DOI: 10.21608/mid.2021.85877.1177 Microbes and Infectious Diseases Journal homepage: https://mid.journals.ekb.eg/ Original article Comparative study between the therapeutic effect of remdesivir versus hydroxychloroquine in COVID-19 hospitalized patients Maii A. Shams Eldeen *1, Mohamed S. Abdelghafar 2, Hoda A. Ibrahim 3, Al Shimaa A. Taha 4, Marwa S. Taha 1 1- Department of Medical Microbiology and Immunology, Faculty of Medicine, Tanta University, Egypt. 2- Department of Anesthesia, Surgical Intensive Care and Pain, Faculty of Medicine, Tanta University. Egypt. 3- Department of Medical Biochemistry, Faculty of Medicine, Tanta University. Egypt. 4- Department of Pharmacology, Faculty of Medicine, Tanta University. Egypt. ARTICLE INFO ABSTRACT Article history: Background: Up till now, no evidence based studies have recommended specific therapeutic modality to treat corona virus disease-19 (COVID-19). Many regimens were tested since the outbreak has started. Among commonly tested drugs are hydroxychloroquine, an antimalarial agent, which was proposed based on its anti-inflammatory as well as antiviral effects and remdesivir, an antiviral that showed invivo and invitro activity against the formerly known corona-viruses The Food & Drug Administration (FDA) approved using remdesivir in the treatment of severe cases of COVID-19. Objectives: To evaluate the effectiveness of remdesivir versus hydroxychloroquine against SARS-CoV-2 in terms of infectivity period in hospitalized COVID-19 patients. Methods: Fifty patients that were clinically diagnosed with Covid-19 admitted to Tanta University Isolation Hospital from June - September, 2020 were included in this study and divided into 2 groups. Group I had hydroxychloroquine as the main therapeutic agent in their treatment regimen, while group II had the antiviral remdesivir instead. Laboratory testing involved nasopharyngeal swabbing which was transported immediately to Tanta University Hospital laboratory for Real-time PCR. Results: There was a significant better outcome and shorter infectivity period in group 2 who received the antiviral remdesivir. Conclusions: Remdesivir showed significant better outcome in COVID19 hospitalized patients, as it reduced period needed for clinical improvement while administration of hydroxychloroquine was not associated with better outcome or increased risk to the patients. Received 30 June 2021 Received in revised form 13 August 2021 Accepted 16 August 2021 Keywords: SARS-CoV-2 Remdesivir Hydroxychloroquine Real-time PCR