Ethanol Vapor May Modulate Early Entry Dynamics of Enveloped Respiratory Viruses

This work proposes a biophysical hypothesis that low-concentration ethanol vapor may transiently modulate the physicochemical properties of viral lipid envelopes at airway gas–liquid interfaces, thereby influencing early entry dynamics of enveloped respiratory viruses. The proposed mechanism suggests that localized ethanol vapor exposure may alter membrane fluidity, restrict spike protein conformational flexibility, and increase the energetic barrier for membrane fusion during host cell entry. These effects may reduce viral entry efficiency without invoking systemic ethanol exposure or therapeutic dosing. The hypothesis is grounded in established principles of membrane biophysics, amphiphile–lipid interactions, and diffusion kinetics. A mechanistic framework is presented integrating viral envelope dynamics, spike conformational changes, and host–virus membrane interactions. This work provides a theoretical framework for understanding physicochemical modulation of viral entry processes and proposes potential directions for experimental validation.