A new study has shown that mask-wearing with other measures such as social distancing nearly equally protect wearers from both transmitting or acquiring infection.

One of the study’s authors, Steffen Eikenberry, noted that “without symptoms, you don’t know if you are infected, and you don’t know if the person standing nearby is either. By wearing a mask you’re protecting yourself, as well as protecting others … the more people wear masks in public, the bigger the benefit is for the overall community.” This applies to ordinary (even homemade) cloth masks for the general public while out in public.

The study is a mathematical model and showed that the level of the public’s embracement of masks was important in reducing spread. The authors also found that delaying the adoption and widespread use of masks may undermine the effectiveness of this measure.

The paper is based on simulated case studies using mortality data compiled by Center for Systems Science and Engineering at John Hopkins University from January 22, 2020, through April 2, 2020, for New York and Washington State. The mass adoption of even relatively poor quality homemade masks had a positive benefit.

The scenario modelled suggested that if 80% of people wear moderately (50%) effective masks, this could prevent 17-45% of projected deaths over two months in New York. In Washington, where baseline transmission is less intense, 80% adoption of relatively low quality (20% effective) masks could reduce mortality by 24-65%.

The authors quickly emphasised that masks are to complement all of the other public health measures advocated to date including social distancing, consistent hand-washing, self-isolation, etc. and not a replacement.

Masks in public not only prevent asymptomatic wearers from transmitting the virus but also have some benefit in protecting uninfected individuals.

Essential service workers including crucial retail outlets, health, law enforcement, etc., are a category of particular concern since they may come into contact with hundreds of persons daily and they may become infected and become superspreaders of disease.

This study suggests that face mask-wearing by the general public should be implemented nationwide without delay until a solution, such as a vaccine, is found. This applies even if masks are homemade and of relatively low quality, as long as these are worn in conjunction with hand-washing, self-isolation and so on.

Clearly, as Einkenberry notes, “the more people wear masks in public, the bigger the benefit is for the overall community”. 

Victor Grech is a consultant paediatrician (Cardiology) at Mater Dei Hospital.