Reduction in SARS-CoV-2 Oral Viral Load with Prophylactic Mouth Rinse

RCT 116 patients in Iran, showing lower short term viral load with mouth rinses chlorhexidine, hydrogen peroxide, and povidone-iodine. Chlorhexidine and hydrogen peroxide were the most effective.

Analysis of short-term changes in viral load using PCR may not detect effective treatments because PCR is unable to differentiate between intact infectious virus and non-infectious or destroyed virus particles. For example Alemany, Tarragó‐Gil perform RCTs with cetylpyridinium chloride (CPC) mouthwash that show no difference in PCR viral load, however there was significantly increased detection of SARS-CoV-2 nucleocapsid protein, indicating viral lysis. CPC inactivates SARS-CoV-2 by degrading its membrane, exposing the nucleocapsid of the virus. To better estimate changes in viral load and infectivity, methods like viral culture that can differentiate intact vs. degraded virus are preferred.

This study is excluded in the after exclusion results of meta analysis: study only provides short-term viral load results.