Wearing a mask dramatically reduces transmission of COVID-19, study finds – .

Wearing a mask dramatically reduces transmission of COVID-19, study finds – .

Coronavirus disease (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continues to spread around the world. As of June 24, 2021, more than 179 million cases of COVID-19 have been reported worldwide, with a death toll of nearly 3.9 million.

Amid the pandemic, non-therapeutic measures to curb the spread of the virus, especially wearing masks, have been effective in some countries. Despite its usefulness, this practice has been viewed as a controversial measure since some community-based studies have reported inconsistent results.

Study: Wearing a mass mask significantly reduces the transmission of COVID-19. Image Credit: Chat Box / Shutterstock.com

Researchers at the University of Bristol have found that an entire population that wears masks in public results in a reduction in the transmission of SARS-CoV-2 by almost 26%. The study, which appeared in the pre-print server medRxiv *, demonstrated that at around the same time the mask warrants were lifted, the persistence of masks wearing by a majority of the population resulted in a notable reduction in the transmission of SARS-CoV-2.

Face masks are one of the most popular interventions for COVID-19, with very high use in most countries. Recently, the worldwide wearing of masks has started to decline, even in countries with low vaccination rates.

It is important to confirm the effectiveness of mask wearing because only a minority of the world’s population is expected to be fully vaccinated by the end of 2021. In addition, the emergence of new variants of SARS-CoV-2 which are highly transmissible and have the potential to evade acquired immunity is also worrisome. The researchers aimed to assess the effectiveness of mask wearing in health facilities and in the community by reviewing previous studies.

Effects of wearing a mask

Masks have at least two effects: preventing viral transmission to uninfected mask wearers and preventing people with COVID-19 from infecting others.

In healthcare settings, N95 masks work well when worn correctly by trained users and have been shown to reduce the transmission of several coronaviruses by at least half, including SARS-CoV-2. Surgical masking of uninfected individuals corresponds to a 65% to 75% reduction in their risk of contracting COVID-19.

Meanwhile, in community settings, clinical studies have shown that fitted surgical masks provide individual meta-analysis results, ranging from a 7% increase in the risk of infection to a 61% decrease in the risk of infection. ‘infection.

Image Credit: ST.art/Shutterstock.com

The study

In the present study, the researchers aimed to assess the ecological effect of a large part of the population wearing medium masks in the community setting. They also want to determine how the effects of wearing a mask vary between different cultures.

The team investigated inconsistencies within epidemiological studies and found that government mask mandates are not linked to a significant increase in mask wear. In addition, the team analyzed the effect of wearing a mask on transmission rates, during which it covered 92 regions in six different countries. Researchers in the current study also included the largest survey of individual-level mask-wearing behaviors that included responses from 20 million participants.

To arrive at the study results, the team used a hierarchical Bayesian model to estimate the effect of mask wear and mask warrants on transmission rates by associating warrants with reported cases in each region.

The researchers also assessed the strength of the results conducted in a total of 123 experiments through 22 sensitivity analyzes. This assessment found that an entire population that wears masks in public spaces results in a median reduction in SARS-CoV-2 reproduction number of 25.8%, with 95% of the medians between 22.2% and 30, 0%.


Taken together, the researchers concluded that wearing face masks is linked to a marked reduction in the transmission of SARS-CoV-2. The study suggests that data from national and state mandates is not sufficient to model the effect of wearing a mass mask.

By comparison, South Korea’s mask-wearing mandate came after voluntary wearing had already reached 94%. Meanwhile, the Netherlands and Switzerland had imposed mask-wearing warrants, but few people wore masks. In the Czech Republic, the wearing of masks increased, but only after the warrant was imposed for a considerable period.

The team also observed that factors other than warrants may have contributed to global mask adoption in 2020.

“This presents a difficulty for political decision-makers: if the port works but the mandates are not strongly associated with the port, what other levers are available? Some options include free mask distribution, home supply guarantees, fitness training, mask quality guidelines, site-targeted mandates, and an openness to mask benefits. ”

*Important Notice

medRxiv publishes preliminary scientific reports which are not peer reviewed and, therefore, should not be considered conclusive, guide clinical practice / health-related behavior, or treated as established information.

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