Salivary and Nasal Detection of the SARS-CoV-2 Virus After Antiviral Mouthrinses (BBCovid): A structured summary of a study protocol for a randomised controlled trial.

- To describe the evolution of the SARS-CoV-2 salivary viral load of patients infected with Covid-19, performing 7 days of tri-daily mouthwashes with and without antivirals. - To compare the evolution of the SARS-CoV-2 nasal and salivary viral load according to the presence or absence of antivirals in the mouthwash. This is a multi-center, randomised controlled trial (RCT) with two parallel arms (1:1 ratio). Inclusion criteria - Age: 18-85 years old - Clinical diagnosis of Covid-19 infection - Clinical signs have been present for less than 8 days - Virological confirmation - Understanding and acceptance of the trial - Written agreement to participate in the trial Exclusion criteria - Pregnancy, breastfeeding, inability to comply with protocol, lack of written agreement - Patients using mouthwash on a regular basis (more than once a week) - Patient at risk of infectious endocarditis - Patients unable to answer questions - Uncooperative patient The clinical trial is being conducted with the collaboration of three French hospital centers: Hospital Center Emile Roux (Le Puy en Velay, France), Clinic of the Protestant Infirmary (Lyon, France) and Intercommunal Hospital Center (Mont de Marsan, France). Eligible participants will be allocated to one of the two study groups. Intervention group: patients perform a tri-daily mouthwash with mouthwash containing antivirals (β-cyclodextrin and Citrox®) for a period of 7 days. patients perform a tri-daily mouthwash with a placebo mouthwash for a period of 7 days. Primary Outcome Measures: Change from Baseline amount of SARS-CoV-2 in salivary samples at 4 and 9 hours, 1, 2, 3, 4, 5 and 6 days. Real-time PCR assays are performed to assess salivary SARS-CoV 2 viral load. Change from Baseline amount of SARS-CoV-2 virus in nasal samples at 6 days. Real-time PCR assays are performed to assess nasal SARS-CoV-2 viral load. Participants meeting all eligibility requirements are allocated to one of the two study arms (mouthwash with β-cyclodextrin and Citrox® or mouthwash without β-cyclodextrin and Citrox®) in a 1:1 ratio using simple randomisation with computer generated random numbers. Participants, doctors and nurses caring for participants, laboratory technicians and investigators assessing the outcomes will be blinded to group assignment. Both the intervention and control groups will be composed of 103 participants, so the study will include a total of 206 participants. The current protocol version is 6, August 4 This trial was registered on 20 April 2020 at www.clinicaltrials.gov with the number NCT04352959 . The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol." The study protocol has been reported in accordance with the Standard Protocol Items: Recommendations for Clinical Interventional Trials (SPIRIT) guidelines (Additional file 2)."