A critical review on the role of leakages in the facemask protection against SARS‐CoV‐2 infection with consideration of vaccination and virus variants

Abstract

The protection provided by facemasks has been extensively investigated since the beginning of the SARS‐CoV‐2 outbreak, focusing mostly on the filtration efficiency of filter media for filtering face pieces (FFP), surgical masks, and cloth masks. However, faceseal leakage is a major contributor to the number of potentially infectious airborne droplets entering the respiratory system of a susceptible individual. The identification of leaking spots and the quantification of leaking flows are crucial to estimate the protection provided by facemasks. This study presents a critical review on the measurement and calculation of facemask leakages and a quantitative analysis of their role in the risk of SARS‐CoV‐2 infection. It shows that the pairing between the mask dimensions and the wearer's face is essential to improve protection efficiency, especially for FFP2 masks, and summarizes the most common leaking spots at the interface between the mask and the wearer's face. Leakage is a crucial factor in the calculation of the protection provided by facemasks and outweighs the filtration performances. The fit factors measured among mask users were summarized for different types of face protection. The reviewed data were integrated into a computational model to compare the mitigation impact of facemasks with vaccination with consideration of new variants of SARS‐CoV‐2. Combining a high adoption rate of facemasks and a high vaccination rate is crucial to efficiently control the spread of highly infectious variants.

Development of Functional Filter Materials for Virus Protective Face Masks

“…However, as with any type of mask, the exact fit of the mask influences its real‐world efficiency. [ 33 ] Indeed, in our experimental setup, we used flat samples, which can be considered to have an ideal fitting.…”

Why Face Masks Should not be Imposed on the Public Again: A Review Article

“…The majority of masks commonly used to reduce the transmission of SARS-CoV-2 can be classified into three categories: highefficiency face protection, also called respiratory protective devices (e.g., filtering facepiece 2, also known as FFP2, and N95) intended for respiratory protection; medical/surgical masks designed for professional use in healthcare settings with generally lower protection efficiencies and looser fit; cloth masks which are inexpensive and often made of everyday cotton fabric (Schmitt & Wang, 2022). For cloth masks, it is usually recommended to have three layers, and they can also be made at home.…”

“…So, the quality of these masks varies widely. Surgical masks and respirators are designed for only a single use because they work by trapping harmful particles inside the mesh of fibers from which they are made (Schmitt & Wang, 2022).…”

“…This intuition is because masks (and indeed any sufficiently dense object or material) can act as a barrier that reduces the amount of larger respiratory secretions that are projected forward or the distance they travel (Jefferson et al, 2011;Liu et al, 2023;Offeddu et al, 2017;Smith et al, 2016). There is also plenty of research showing how well different fabrics used to make masks can filter out particles (Matuschek et al, 2020;Schmitt & Wang, 2022).…”

AI‐Driven Design System for Fabrication of Inhalable Nanocatchers for Virus Capture and Neutralization

“…[5] Nevertheless, the virus present in the environment can still be transmitted via alternative mucosal tissues or in the absence of protective equipment, such as during meals and meetings. [6][7][8] Hence, the effective control of viral spread can be achieved if a technology capable of suppressing the virus in the environment and deactivating it prior to encountering the human body exists. However, current environmental disinfectants like alcohol and hypochlorous acid can only be utilized for surface or partial space disinfection, and they exhibit considerable side effects on the human body.…”