Math Shows How Widespread Facemask Use Is Vital to Suppress the COVID Pandemic As Lockdowns Lift

Scientists say widespread use of face masks is vital to quell the coronavirus pandemic as lockdowns intensify.

A new mathematical model suggests that the relaxation of lockdown should be accompanied by wider and more effective use of control measures such as face masks, even with vaccination, to more quickly suppress COVID-19 and reduce the likelihood of a new lockdown.

The model, developed by scientists from the Universities of Cambridge and Liverpool, was recently published in the Journal of the Royal Society Interface. It uses mathematical equations to provide general insights on how COVID-19 will spread under various potential control scenarios.

Control measures involving face masks, washing hands, and close-range (1-2 meters) social distance can all limit the number of virus particles spread between people. These are called ‘non-spatial’ measures to distinguish them from a second category of ‘spatial’ controls, including lockdown and travel restrictions, that reduce the spread of virus particles. The new model compares the effectiveness of different combinations of measures in controlling the spread of COVID-19, and shows how non-spatial control should be increased when lockdown is lifted.

“A more effective use of control measures such as face masks and hand washing would help us to stop the pandemic more quickly, or to get better results in stopping transmission through the vaccination program. This also means that we can prevent a new potential blockage, ”said Dr. Yevhen Suprunenko, a research associate in the Department of Plant Sciences at Cambridge University and lead author of the paper. The authors emphasize that their predictions rely on effective implementation of such non-spatial management measures.

The model also took into account the socio-economic impact of both types of measures and how it changes during the pandemic. The socio-economic consequences of spatial measures such as lockdown have increased over time, while the costs of non-spatial management measures have decreased – for example, face masks have become more widely available and people have become accustomed to wearing them.

“Measures such as lockdowns that limit how far potentially infected people move can have a stronger impact on controlling the spread of disease, but methods that reduce the risk of transmission when people mix offer an inexpensive way to supplement them”, said Dr. Stephen Cornell of the University of Liverpool, co-author of the paper.

The model arose from a broader research program to identify control strategies for plant diseases that threaten staple crops. Using a mathematical approach rather than a conventional computer simulation model, the authors were able – for a wide variety of scenarios – to identify general insights on how to deal with newly emerging plant and animal infectious diseases.

“Our new model will help us study how different infectious diseases can spread and become endemic. This will allow us to find better control strategies and to stop future epidemics faster and more efficiently, ”said Professor Chris Gilligan from the University of Cambridge’s Department of Plant Sciences, co-author of the paper.

Reference: “Analytical approach to invasion and endemic thresholds, and the optimal control of epidemics in spatially explicit individual models” by Yevhen F. Suprunenko, Stephen J. Cornell and Christopher A. Gilligan, March 31, 2021, Journal of the Royal Society Koppel.
DOI: 10.1098 / rsif.2020.0966