Disinfectants with "virucidal activity against enveloped viruses" effective against SARS-CoV-2

By Susha Cheriyedath, M.Sc.Nov 11 2020

The World Health Organization (WHO) declared the ongoing coronavirus disease (COVID-19) outbreak caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a public health emergency of international concern on 30 January 2020. This is the WHO's highest level of alarm concerning infectious diseases. On a global basis, the SARS-CoV-2 virus has infected over 52 million people and caused 1.28 million pandemic-related deaths in the past ten months. The week starting 5 October through 11 October 2020 saw over 2.2 million new SARS CoV-2 infections and 39,000 COVID-19 associated deaths, the highest number per week reported at up until that date in the ongoing COVID-19 pandemic.

Effective hygiene measures are critical in the context of SARS-CoV-2 pandemic

To prevent further spreading of the SARS-CoV-2 virus, the WHO recommended some hygiene measures, including the use of 70% ethanol to disinfect hands and surfaces. Effective disinfection measures are crucial to support strategies for the prevention of transmission of the virus worldwide.

Methodological framework-based guidance from the European Committee for standardization could help in choosing disinfectants that effectively target the virus. The committee's framework as well as the German Robert-Koch-Institute, advise that antiseptics and disinfectants claiming "virucidal activity against enveloped viruses" can be effective against all kinds of enveloped viruses, including coronaviruses like SARS-CoV-2. Despite this guidance, questions arise about the efficacy of certain formulations against SARS-CoV-2 during the ongoing SARS-CoV-2 pandemic.

Study: Virucidal efficacy of different formulations for hand and surface disinfection targeting SARS CoV-2. Image Credit: Robert Kneschke / Shutterstock

This news article was a review of a preliminary scientific report that had not undergone peer-review at the time of publication. Since its initial publication, the scientific report has now been peer reviewed and accepted for publication in a Scientific Journal. Links to the preliminary and peer-reviewed reports are available in the Sources section at the bottom of this article. View Sources

Study investigates the efficacy of typical disinfectants against SARS-CoV-2

A recent study by a team of researchers from the Schülke & Mayr GmbH, Kiel University of Applied Sciences, Ruhr University Bochum, European Virus Bioinformatics Center (EVBC), West German Centre of Infectious Diseases, and University of Duisburg-Essen, Germany, demonstrated that two commercially available surface disinfectant formulations and one hand disinfection formulation that claim "virucidal activity against enveloped viruses" are effective in inactivating the SARS-CoV-2 virus. Their study has been published on the preprint server bioRxiv*.

This study aimed to investigate the efficacy of 3 typical formulations used for surface or hand disinfection against SARS-CoV-2 using the European Standard EN 14476 protocol. Efficacy data related to SARS-CoV-2 was compared to data obtained using the surrogate test virus vaccinia as per EN 14476 and the German DVV/RKI guideline.

SARS-CoV-2 is more susceptible than standard test virus to alcoholic formulations

This study's findings show that enveloped viruses such as SARS-CoV-2 are more susceptible to the alcoholic biocidal formulations tested compared to the enveloped MVA, which is an established surrogate standard test virus in European and German test protocols. The data obtained from this study also shows that SARS-CoV-2 is at least equally susceptible to quaternary ammonium compounds (QAC)-based formulations compared to the standard test virus.

Preliminary data from the study shows more limited stability of SARS-CoV-2 to the QAC-based formulation when compared to the vaccinia virus. This will need to be verified further in future studies. The team says that their findings agree with recently published data that indicate good efficacy of QAC-based formulations against three different strains of SARS-CoV-2 within a contact time of 30 s.

"Preliminary data from our lab even indicate a more limited stability of SARS-CoV-2 to the QAC-based formulation when compared to vaccinia virus, which needs to be verified in future studies."

According to the authors, their study undermines the validity of the surrogate test strain concept established by national and international institutions such as the European Standardization Committee. This aligns with past data investigating the chemical susceptibility of the pathogen Candida auris compared to the surrogate test organism Candida albicans. In this study and in the earlier study, the surrogate test organisms were found to be more resistant to the chemical disinfectants tested than the targeted organism.

Thus, the authors concluded that based on the surrogate concept, chemical disinfectants that claim "virucidal activity against enveloped viruses" effectively target enveloped SARS-CoV-2 viruses and are safe to use as a preventive measure.

"In the present study as well as in the above mentioned earlier study the surrogate test virus and the surrogate test yeast, respectively, were found to be more resistant to the applied chemical disinfectants then the targeted outbreak organism."

This news article was a review of a preliminary scientific report that had not undergone peer-review at the time of publication. Since its initial publication, the scientific report has now been peer reviewed and accepted for publication in a Scientific Journal. Links to the preliminary and peer-reviewed reports are available in the Sources section at the bottom of this article. View Sources