2026-04-13 北海道大学
本研究成果の概要図
＜関連情報＞
- https://www.hokudai.ac.jp/news/2026/04/cpcsars-cov-2covid-19.html
- https://www.hokudai.ac.jp/news/pdf/260413_pr.pdf
- https://www.sciencedirect.com/science/article/abs/pii/S134900792600040X?via%3Dihub
COVID-19患者唾液中SARS-CoV-2に対するセチルピリジニウム塩化物水和物の抗ウイルス効果（観察研究） Antiviral effect of cetylpyridinium chloride on SARS-CoV-2 in patients with COVID-19: An Observational Study
Ryo Takeda, Hirofumi Sawa, Michihito Sasaki, Yasuko Orba, Nako Maishi, Takuya Tsumita, Yoichi Ohiro, Akira Hasebe, Hidehiko Sano, Yoshimasa Kitagawa, Kyoko Hida, Yasuhiro Hida
Journal of Oral Biosciences Available online: 9 March 2026
DOI:https://doi.org/10.1016/j.job.2026.100772
Abstract
Objectives
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the viral agent responsible for the COVID-19 pandemic and primarily invades the body through the oral cavity. Cetylpyridinium chloride (CPC), a widely used component of oral care products, has demonstrated antiviral effects against SARS-CoV-2; however, the clinical evidence remains limited. This study investigated the virucidal effects of oral CPC in patients with COVID-19 and its impact on reverse transcription polymerase chain reaction (RT-PCR) positivity.
Methods
Thirty-four patients with COVID-19 were initially recruited after obtaining positive PCR test result. This study was conducted during a nationwide Delta-variant–driven epidemic characterized by high viral loads and enhanced transmissibility. Saliva was collected at seven predefined time points to assess the effects of CPC-containing tablets and mouthwash. Viral RNA levels and infectious viral titers were quantified using qRT-PCR and plaque assays. Sixteen patients with detectable SARS-CoV-2 RNA in baseline saliva samples who completed all scheduled samplings constituted the final analytical cohort.
Results
During the Delta-variant–predominant period, CPC-containing tablets reduced both SARS-CoV-2 RNA levels and viral infectivity in saliva. In contrast, CPC-containing mouthwashes did not significantly reduce viral RNA levels compared to baseline samples. The RT-PCR positivity rates after CPC use varied according to the applied cycle threshold (Ct) cutoff values.
Conclusions
CPC-containing tablets transiently decrease the SARS-CoV-2 salivary viral load and infectivity and may help reduce the risk of transmission in public settings. When CPC formulations are used prior to saliva-based PCR testing, the Ct cut-off values may require adjustment.
Clinical significance
Despite challenges in conducting saliva-based clinical research in COVID-19 patients, this study provides clinical evidence supporting the antiviral efficacy of CPC formulations on salivary SARS-CoV-2 during the Delta-variant pandemic.
