Early mask use should be considered if community transmission is present, as this has a greater effect than later mask-wearing mandates.
Valentina Costantino, Professor Raina MacIntyre


To estimate the impact of universal community face mask use in the COVID-19 second wave in Victoria in 2020, Australia, along with other routine disease control measures in place, timing, and varying mask effectiveness and uptake.


A six-week lockdown with standard control measures, but no masks, would have resulted in a large resurgence by September, following the lifting of restrictions. Mask use can substantially reduce the epidemic size, with a greater impact if at least 50% of people wear a mask which has an effectiveness of at least 40%. Early mask use averts more cases than mask usage that is only implemented closer to the peak. No mask use, with a 6-week lockdown, results in 67,636 cases and 120 deaths by 1 October 2020 if no further lockdowns are used. If mask use at 70% uptake commences on 23 July 2020, this is reduced to 7,961 cases and 42 deaths. Upon calibrating the model to observed epidemiological data showing a rate of mask usage of 75%, we estimated community mask effectiveness to be 11%.

Mask use can substantially improve epidemic control if its uptake is higher than 50% and if moderately effective masks are used.

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First published: Apr 21, 2021
Biosecurity Program, Kirby Institute
The Biosecurity Program (BSP) at the Kirby Institute, University of New South Wales conducts research on pandemics, epidemics, emerging infections and the control of these through pharmaceutical and non-pharmaceutical measures.