Personal care formulations demonstrate virucidal efficacy against multiple SARS-CoV-2 variants of concern: implications for hand hygiene

ABSTRACT

The second and third waves of COVID-19 pandemic have largely been driven by the surge of successive SARS-CoV-2 variants of concern (VOC). These VOC have rapidly spread through multiple geographies being enabled by high transmission rates and/or high viral load compared to the original parent strain. Consequently, the altered phenotypes of these VOC have posed greater challenges to diagnostic and clinical management of COVID-19. Despite considerable progress being made on vaccine roll out, practicing proper hand hygiene has been advocated as a consistent precautionary intervention as more virulent VOC continue to emerge and spread across geographies. Two variants of concern, namely beta and delta, have recently been shown to escape antibody-mediated neutralization by virtue of acquired mutations in the receptor-binding domain of the viral spike protein which binds to the human ACE2 receptor for cellular entry. In this report we have empirically determined the efficacy of a range of personal care formulations in inactivating the beta and delta variants of SARS-CoV-2. High titres of these variants were exposed to marketed personal care formulations from Unilever under standard in-vitro suspension test-based conditions relevant to end-user habits. All the formulations demonstrated greater than 99.9% reduction in viral infective titres. The rate of inactivation by these products were comparable to that of the original strain of SARS-CoV-2 virus tested under the same conditions. Therefore, it can be concluded that well-designed personal care formulations when tested under consumer-centric conditions, and with proven efficacy against the parent strain of SARS-CoV-2 will continue to be effective against extant and emerging variants of SARS-CoV-2. This is through their broad-spectrum mode of action (disruption of lipid bilayer of the host-derived viral envelope, denaturation of envelop and nucleocapsid proteins, and disruption of genome) which is independent of the escape mutations that facilitate immune evasion or enhanced transmissibility.