Successful Reduction of SARS-CoV-2 Viral Load by Photodynamic Therapy (PDT) Verified by QPCR – A Novel Approach in Treating Patients in Early Infection Stages

By: Hans Michael Weber, Yasaman Zandi Mehran, Armin Orthaber, Hadi Hosseini Saadat, Robert Weber, and Matthias Wojcik



The Covid-19 pandemic is affecting Global Health and the world‘s economy dramatically since early 2020. After a temporary slowdown in summer 2020 the infection numbers and death rates have been increasing again in recent months leading to various restrictions of social and economic life in many countries. Latest developments of new vaccinations seem to be promising; however large-scale production and worldwide distribution logistics take time while questions such as longevity of immune protection, long-term side-effects etc. are remaining unclear at this point. Furthermore, vaccination is a preventive approach and not a therapy for acutely infected patients. Thus, there are still therapies needed to help people with Covid-19 infections. The objective of this study was to evaluate if Photodynamic Therapy (PDT) with Riboflavin and a specially designed light treatment kit would be able to fill this gap by helping people in early stages of infection. This may lead to a relief for hospitals and intensive care stations.


This study was made up of two groups with 20 patients each with the experiment (verum) group receiving Photodynamic Therapy and daily testing and a control group receiving conventional care plus testing. All patients in both groups had positive Covid-19 test results at the beginning of the study. They were in an early infection stage with mild symptoms like fever, dry cough, headache, hard breathing, fatigue etc. QPCR tests with Ct-viral load were performed on day 1, 2, 3, 4, 5 and 7 in theexperiment group and on day 1, 3, 5 and 7 in the control group.Results:All 20 patients in the experiment group showed significant improvement in clinical symptoms and viral load assessment within the 5 days of PDT treatment. 14 out of 20 patients had a negative QPCR test after 5 days of treatment with PDT while the other 6 patients also showed significantly reduced viral load. 20 patients in the control group with conventional care were tested 3 times within 5 days and no significant improvement could be seen, neither clinically nor in viral load assessment.


In this primary study the potential of Photodynamic Therapy (PDT) against SARS-CoV-2 could be shown in early infection stages. PDT proved to be successful in improving clinical symptoms, lowering viral loads and in preventing hospitalization and intensive care treatments. Th e applied treatment is easy to perform at home and it is cost effective. It can be used for prevention after contact with infected people or in case of positive testing but also in early cases with mild to moderate clinical symptoms.