In a big shift from its earlier position, the WHO has issued new guidelines that say everyone should wear a three-layer fabric or non-medical mask in public to prevent the spread of the  Covid-19.

WHO Director-General Tedros Adhanom Ghebreyesus said people over age 60 or with underlying medical conditions also should wear masks in situations where social distancing cannot be maintained. WHO advises that governments should encourage the general public to wear masks where there is widespread transmission and physical distancing is difficult, such as on public transport, in shops or in other confined or crowded environments."

Based on this new research, WHO advises that fabric masks should consist of at least three layers of different material. Those wearing a cloth mask should choose a three-layer fabric mask made of absorbent cotton closest to the face, followed by a polypropylene layer and then a synthetic layer that is fluid-resistant, WHO said.

According to cnn- The review of various published studies, paid for by the World Health Organization, had three main findings:

• Physical distancing: The chance of transmission at a distance of less than 1 meter (3.3 feet) was 12.8%, while that fell to 2.6% at a distance of more than 1 meter (3.3 feet). It added that distances of 2 meters (6.6 feet) could be more effective. It said that the certainty of the evidence was "moderate."
• Face masks: The chance of transmission without a face mask or respirator (like an N95 mask) was 17.4%, while that fell to 3.1% when a mask was worn. However, the certainty of the evidence was "low."
• Eye protection: The chance of transmission without eye protection was put at 16%, compared to 5.5% with some form of eye protection as a face shield, visor, goggles or glasses. However, the certainty of the evidence was "low."

Source: hindustantimes,businessinsider, cnn