Sir, – Stephen Bruce asks us if "…now might be a good time to question rather than comply?" when it comes to face coverings (Letters, December 14th). Allow me then to provide at least one answer, to the assumed question: are masks effective? I'll even include the references for those so inclined.
A systematic review analysis published in The Lancet (Chu et al 2020; 395: 1973-87) stated face masks could result in a large reduction in risk of infection, with a stronger effect seen with respirators compared to disposable surgical or reusable masks. Admittedly, most of the studies investigated were in a healthcare setting where staff would have training on how to don and doff personal protective equipment.
In the American Society of Tropical Medicine and Hygiene, Leffler et al (103(6), 2020, pp. 2400-2411) investigated how public mask-wearing affected coronavirus mortality.
Data showed that in countries with either cultural norms or early government policies supporting public mask-wearing, mortality rates increased about 16 per cent per week. However, in countries where there was no norm or delayed government policies supporting mask-wearing, the rates of increase was 62 per cent per week.
While the number of cases of Covid-19 increased after mask-wearing was introduced, there is often a delayed effect when new measures are introduced. For example, in 1968, seat belts became mandatory in the US, yet it was only from 1973 that there was a downward trend of motor vehicle fatalities.
But face coverings go beyond blocking inhaled and exhaled droplets. They can act as a visual reminder of shared responsibility. There is some evidence to suggest that donning a face covering might lead to the wearer and those around them to adhere better to other public health measures, including physical distancing (Marchiori arXiv:2005.12446).
Many tend to talk about individual rights, but few talk of individual responsibilities. Face coverings are one of many personal and shared responsibilities to combat the Covid-19 pandemic, as explained recently in your paper (The Swiss cheese model of Covid-19 defence: What it means, how it works, December 14th).
Those who can follow public health measures should, to protect those who cannot. – Yours, etc,
Dr PAUL LAVIN,
Dublin 6W.