Comparative evaluation of chlorous acid and sodium hypochlorite activity against SARS-CoV-2

Noritoshi Hatanaka; Sharda Prasad Awasthi; Bingting Xu; Hisataka Goda; Hiroyuki Kawata; Isanori Horiuchi; Mayo Yasugi; Shinji Yamasaki

doi:10.1099/acmi.0.000354

Comparative evaluation of chlorous acid and sodium hypochlorite activity against SARS-CoV-2

Access Microbiol. 2022 May 23;4(5):acmi000354. doi: 10.1099/acmi.0.000354. eCollection 2022 Aug.

Authors

Noritoshi Hatanaka^{1

2

3}, Sharda Prasad Awasthi^{1

2

3}, Bingting Xu¹, Hisataka Goda⁴, Hiroyuki Kawata⁴, Isanori Horiuchi⁴, Mayo Yasugi^{1

2

3}, Shinji Yamasaki^{1

2

3}

Affiliations

¹ Graduate School of Veterinay Science, Osaka Metropolitan University, 1-58, Rinkuourai-kita, Izumisano, Osaka 598-8531, Japan.
² Asian Health Science Research Institute, Osaka Metropolitan University, 1-58, Rinkuourai-kita, Izumisano, Osaka 598-8531, Japan.
³ Osaka International Research Center for Infectious Diseases, Osaka Metropolitan University, 1-58, Rinkuourai-kita, Izumisano, Osaka 598-8531, Japan.
⁴ Sankei Co. Ltd., 2-2-53, Siromi, Chuou-ku, Osaka 540-0001, Japan.

Abstract

A novel coronavirus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), suddenly emerged in China in 2019, spread globally and caused the present COVID-19 pandemic. Therefore, to mitigate SARS-CoV-2 infection effective measures are essential. Chlorous acid (HClO₂) has been shown to be an effective antimicrobial agent. However, at present there is no experimental evidence showing that HClO₂ can inactivate SARS-CoV-2. Therefore, in this study, we examined the potential of HClO₂ to inactivate SARS-CoV-2 in presence or absence of organic matter and the results were compared with that of sodium hypochlorite (NaClO), another potent antimicrobial agent. When concentrated SARS-CoV-2 was incubated with 10 ppm HClO₂ for 10 s, viral titre was decreased by 5 log of 50% tissue culture infective dose per mL (TCID₅₀ ml^-1). However, the same concentration of NaClO could not inactivate SARS-CoV-2 as effectively as HClO₂ did even after incubation for 3 min. Furthermore, 10 ppm HClO₂ also inactivated more than 4.0 log of TCID₅₀ within 10 s in the presence of 5 % fetal bovine serum used as mixed organic matters. Our results obtained with HClO₂ are more effective against SARS-CoV-2 as compared to NaClO that can be used for disinfectant against SARS-CoV-2 .

Keywords: Chlorous acid; SARS-CoV-2; Sodium hypochlorite.