How effective are facemasks in controlling the spread of COVID-19?

Facemask, Quarantine, Coronavirus, Middle East

Bottom Line:

Mathematical modelling data suggests that widespread adoption of facemasks by the public can prevent subsequent waves of COVID-19.


Stutt, R.O.J.H. et al. A modelling framework to assess the likely effectiveness of facemasks in combination with ‘lock-down’ in managing the COVID-19 pandemic. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences (2020).

Date Published:

10 June 2020


The benefits of widespread facemask use during the COVID-19 mask has been widely debated. To determine whether the widespread adoption of facemasks by the public is effective in slowing down the spread of COVID-19, researchers in Britain developed mathematical models to examine the dynamics of COVID-19 spread when facemasks are worn by the public, with or without periods of lockdown. The results of their model showed that when facemasks are used by the public all the time, the reproduction number of the virus (i.e. number of people that will be infected from one case) can be reduced to under one. Furthermore, when used in combination with lockdown policies, widespread wearing of facemasks may flatten subsequent waves of COVID-19, thereby effectively controlling the pandemic. These results hold true even if the assumption is made that facemasks are only 50% effective at capturing virus exhaled from a user’s mouth. The findings from this study could explain why countries that were quick to adopt mandatory facemask policies were able to effectively reduce the spread of COVID-19 (although there are certainly other contributing factors).

Summary by: Louis Huynh