key: cord-330031-c1n994j6
authors: Kratzel, Annika; Todt, Daniel; V’kovski, Philip; Steiner, Silvio; Gultom, Mitra L.; Thao, Tran Thi Nhu; Ebert, Nadine; Holwerda, Melle; Steinmann, Jörg; Niemeyer, Daniela; Dijkman, Ronald; Kampf, Günter; Drosten, Christian; Steinmann, Eike; Thiel, Volker; Pfaender, Stephanie
title: Efficient inactivation of SARS-CoV-2 by WHO-recommended hand rub formulations and alcohols
date: 2020-03-17
journal: bioRxiv
DOI: 10.1101/2020.03.10.986711
sha: 
doc_id: 330031
cord_uid: c1n994j6

The recent emergence of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing COVID-19 is a major burden for health care systems worldwide. It is important to address if the current infection control instructions based on active ingredients are sufficient. We therefore determined the virucidal activity of two alcohol-based hand rub solutions for hand disinfection recommended by the World Health Organization (WHO), as well as commercially available alcohols. Efficient SARS-CoV-2 inactivation was demonstrated for all tested alcohol-based disinfectants. These findings show the successful inactivation of SARS-CoV-2 for the first time and provide confidence in its use for the control of COVID-19. Importance The current COVID-19 outbreak puts a huge burden on the world’s health care systems. Without effective therapeutics or vaccines being available, effective hygiene measure are of utmost importance to prevent viral spreading. It is therefore crucial to evaluate current infection control strategies against SARS-CoV-2. We show the inactivation of the novel coronavirus for the first time and endorse the importance of disinfectant-based hand hygiene to reduce SARS-CoV-2 transmission.

The recent emergence of Severe acute respiratory syndrome coronavirus 2 (SARS-2 CoV-2) causing COVID-19 is a major burden for health care systems worldwide. It is 3 important to address if the current infection control instructions based on active 4 ingredients are sufficient. We therefore determined the virucidal activity of two 5 alcohol-based hand rub solutions for hand disinfection recommended by the World 6

Health Organization (WHO), as well as commercially available alcohols. Efficient 7 SARS-CoV-2 inactivation was demonstrated for all tested alcohol-based disinfectants. 8

These findings show the successful inactivation of SARS-CoV-2 for the first time and 9 provide confidence in its use for the control of COVID-19. Effective hand hygiene is crucial to limit virus spread. Therefore, easily available but 7 efficient disinfectants are crucial. The World Health Organization's 'Guidelines for 8

Hand Hygiene in Health Care' suggests two alcohol-based formulations for hand 9 sanitization to reduce pathogen infectivity and spreading. These recommendations are 10 based on fast-acting and broad-spectrum of microbicidal activity, as well as easy 11 accessibility and safety 3 . We have previously shown that WHO formulation I and II 12 were able to inactivate the closely related SARS-CoV and MERS-CoV 6 Results 20 SARS-CoV-2 was highly susceptible to the WHO formulations (Fig. 1) . WHO 21 formulation I, based on 85 % ethanol, efficiently inactivated the virus with reduction 22 factors (RFs) of  5.9 and concentrations between 40 % -80 % (Fig. 1A) . Subsequent 23 regression analysis revealed similar inactivation profiles compared to SARS-CoV, 24 1 pathogenic human CoVs (Fig. 1A) . WHO formulation II, which is based on 75 % 2 isopropanol, demonstrated a better virucidal effect at low concentrations, with 3 complete viral inactivation and RFs of  5 at a minimal concentration of 30 % (Fig.  4   1B) . The regression analysis showed an inactivation profile of SARS-CoV-2, which 5 was in between SARS-CoV, BCoV and MERS-CoV (Fig. 1B) . 6

Next, we addressed the susceptibility of SARS-CoV-2 against the individual 7 components of the WHO recommended formulations which are also the main 8 ingredients of commercially available hand disinfections. Both alcohols, ethanol (Fig.  9 2A) and 2-propanol ( Fig. 2B) were able to reduce viral titers in 30 s exposure to 10 background levels with RFs between  4.8 and 5.9 after 30 sec. Furthermore, we could 11

show that a minimal concentration of 30 % ethanol or 2-propanol is sufficient for viral 12 inactivation (Fig. 2) . 

Identification of a novel coronavirus in 2 patients with severe acute respiratory syndrome

Isolation of a Novel Coronavirus from a Man with Pneumonia in Saudi Arabia

WHO Guidelines on Hand Hygiene in Health Care

Severe acute respiratory 10 syndrome coronavirus 2 (SARS-CoV-2) and coronavirus disease-2019 (COVID-11 19): The epidemic and the challenges

Coronavirus COVID-19 Global Cases

Virucidal activity of world health 15 organization-recommended formulations against enveloped viruses, including 16 zika, ebola, and emerging coronaviruses

Persistence of coronaviruses on 19 inanimate surfaces and its inactivation with biocidal agents

Virucidal efficacy of peracetic acid for 22 instrument disinfection