Revealed: Different situations, conditions and how face masks work to protect you from COVID-19

A new study reveals under which conditions and in which ways face masks reduce individual and population-average risks of being infected with COVID-19.

Since the beginning of the COVID-19 pandemic, scientists and healthcare professionals have been insisting on the importance of wearing a high-quality face mask to prevent the spread of the virus. In the initial days of the pandemic, this even led to an acute shortage of N95 masks. Even healthcare professionals were hit by this scarcity. But soon, experts said that even home-made cloth masks are equally effective, and many companies and enterprising people came forward to cater to the demand for face masks. Of course, the matter of material and layers also changed over the course of time. Now, during the devastating second wave of the pandemic, experts said that double masking is the way to stop transmission and be safe and people started wearing a surgical mask below their N95 or three-layered cloth mask.

Against this backdrop, we have researchers from the Max Planck Institute for Chemistry in Germany's Mainz who says that they have found under which conditions and in which ways, face masks actually reduce individual and population-average risks of being infected with COVID-19 and help mitigate the coronavirus pandemic. The journal Science published this study.

Surgical masks are okay for most situations

According to the researchers of this study, in most environments and situations, even a simple surgical mask can effectively reduce the transmission of SARS-CoV-2 and the effective reproduction number for COVID-19. They say that for the airborne transmission of COVID-19, usually, just a minor fraction of exhaled respiratory particles contains viruses. Most environments and contacts are under virus-limited conditions where face masks, including simple surgical masks, are highly effective in preventing the spread of Covid-19.

Densely-occupied indoor spaces need N95

The researchers say that in environments with potentially high airborne virus concentrations such as medical settings and densely-occupied indoor spaces, masks with higher filtration efficiency (N95/FFP2) should be used. This is not all. Wearing of masks in such situations must be combined with other protective measures like intensive ventilation. But they reiterated that in most situations, even simple surgical masks are effective. But still, the combination of high-efficiency masks with other protective measures like good ventilation is very important for hospitals, medical centres, and other indoor environments, where high risk patients may encounter high virus concentrations.

Masks important for vaccinated people in all situations too

Masks will remain an important protective measure against SARS-Cov-2 infection -- even for vaccinated persons, especially when the protection provided by vaccination decreases over time, researchers say. The research team came to these conclusions by analysing observational data and a novel quantitative model of airborne virus exposure. This helped them elucidate how the efficacy of face masks depends on characteristic regimes of airborne virus concentration. Researchers are confident that this approach can be used to assess protection against more infectious mutants of Covid-19. It is also applicable to a wide range of respiratory viruses and diseases, including coronaviruses, rhinoviruses, and influenza. The findings showed that aerosol transmission does not necessarily lead to very high reproduction numbers as observed for measles, and that relatively low reproduction numbers do not rule out airborne transmission.

(With inputs from IANS)