Figure 1. Virucidal activity of original and modified World Health Organization (WHO)–recommended hand rub formulations I and II for inactivating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The means of 3 independent experiments with SDs (error bars) and percentage of inactivation at different concentrations are shown. A) WHO original formulation I; B) WHO original formulation II; C) WHO modified formulation I; D) WHO modified formulation II. Insets in panels C and D show regression analyses of the inactivation of coronaviruses. Dark gray bar shows cytotoxic effects, calculated analogous to virus infectivity. Reduction factors are included above the bar. Dilutions of the WHO formulations ranged from 0–80% with an exposure time of 30 s. Viral titers are displayed as TCID50/mL values. BCoV, bovine coronavirus; LLOQ, lower limit of quantification; MERS-CoV, Middle East respiratory syndrome coronavirus; SARS-CoV, severe acute respiratory syndrome coronavirus; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; TCID50/mL, 50% tissue culture infectious dose.