Use of an antiviral mouthwash as a barrier measure in the sars-cov-2 transmission in adults with asymptomatic to mild COVID-19: a multicenter, randomized, double-blind controlled trial

Carrouel, Florence; Valette, Martine; Gadea, Emilie; Esparcieux, Aurélie; Illes, Gabriela; Langlois, Marie Elodie; Perrier, Hervé; Dussart, Claude; Tramini, Paul; Ribaud, Mélina; Bouscambert-Duchamp, Maude; Bourgeois, Denis

OBJECTIVES: To determine if commercially available mouthwash with ß-cyclodextrin and citrox (bioflavonoids) (CDCM) could decrease the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) salivary viral load. METHODS: In this RCT, SARS-CoV-2 PCR-positive patients aged 18-85 years with asymptomatic to mild COVID-19 symptoms <8 days were recruited. A total of 176 eligible patients were randomly assigned (1:1) to CDCM or placebo. Three rinses daily were performed for 7 days. Saliva sampling was performed on day 1 at 9 a.m. (T1), 1 p.m. (T2) and 6 p.m. (T3). On the following 6 days, one sample was taken at 3 p.m. Quantitative RT-PCR was used to detect SARS-CoV-2. RESULTS: The intention-to-treat analysis demonstrated that, over the course of one day, CDCM was significantly more effective than placebo 4 hours after the first dose (p=0.036), with a median percentage (log10 copies/mL) decrease T1-T2 of -12.58% [-29.55% - -0.16%]. The second dose maintained the low median value for the CDCM (3.08 log(10) copies/mL [0 - 4.19]), compared to placebo (3.31 [1.18 - 4.75]). At day 7, there was still a greater median percentage (log(10) copies/mL) decrease in salivary viral load over time in the CDCM group (-58.62% [-100% - -34.36%]) compared to placebo group (-50.62% [-100% - -27.66%]). These results were confirmed by the per-protocol analysis. CONCLUSIONS: This trial supports the relevance of using CDCM on day 1 (4 hours after the initial dose) to reduce the SARS-CoV-2 viral load in saliva. For long term effect (7 days), CDMC appears to provide a modest benefit compared to placebo in reducing viral load in saliva.