The "most comprehensive study to date" found that physical distance and perhaps the use of a mask were the best ways to prevent coronavirus transmission, CNN reports.

The study, published in the Lancet medical journal Monday, June 1, found people should stay at least three feet (1 meter) apart -- and more if possible.

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 like a face shield, visor, goggles or glasses. However, the certainty of the evidence was "low."

There are now more than 6.2 million cases of the novel coronavirus worldwide, including over 2.6 million recoveries so far, according to Johns Hopkins University, which is tracking figures from the World Health Organization and additional sources.

Since the beginning of the outbreak, more than 375,000 people have died globally from Covid-19 complications.