Impacts of host factors on susceptibility to SARS-CoV-2 infection and COVID-19 progression.

SARS-CoV-2, identified in Wuhan, China, in December 2019, is the third coronavirus responsible for a global epidemic, following SARS-CoV (2002) and MERS-CoV (2012). Given the recent emergence of COVID-19, comprehensive immunological data are still limited. The susceptibility and severity of SARS-CoV-2 infection are influenced by various host factors, including hormonal changes, genetic variations, inflammatory biomarkers, and behavioral attitudes. Identifying genetic factors contributing to infection severity may accelerate therapeutic development, including drug repurposing, natural extracts, and post-vaccine interventions (Initiative and Covid, 2021). This review discusses the human protein machinery involved in (a) SARS-CoV-2 host receptors, (b) the human immune response, and (c) the impact of demographic and genetic differences on individual risk for COVID-19. This review aims to clarify host factors implicated in SARS-CoV-2 susceptibility and progression, highlighting potential therapeutic targets and supportive treatment strategies.