Two-meter distancing might halve infection risk compared to one meter, according to a new review analysis in The Lancet. 

The researchers combed through 172 observational studies across 16 countries and then applied statistical analysis to pull out estimates of of risk of infection. The models they used on nine key studies found that transmission of viruses was lower with physical distancing of 1 m or more, compared with a distance of less than 1 m; protection was increased as distance was lengthened .

Face mask use could result in a large reduction in risk of infection, with stronger associations with N95 or similar respirators compared with disposable surgical masks or similar. Eye protection also was associated
with less infection .

The transmission risk when people stood at least one meter away was around 3%, but rose to 13% when people were standing within one meter. The risk of transmission roughly halves for every extra meter of distancing up to three meters, the modeling suggested.

Masks, too: The researchers also found that both face coverings and eye protection significantly reduce the risk of spreading the virus: the studies found that masks cut the risk of infection from 17% to 3% while eye protection reduces it from 16% to 6%.

Governments around the world are discussing how to ensure people’s safety while lifting lockdown restrictions. It’s clear from this peer-reviewed paper that keeping people as physically apart from each other as possible has to be at the core of any sensible strategy. The findings should also inform workplaces, restaurants, bars, and movie theaters that are currently trying to work out how to get people back through their doors while protecting them from spreading covid-19 to each other.

Differing approaches: Distancing advice varies from country to country. In the UK it’s two meters currently, although there is some pressure to reduce that distance. In the US, the CDC advises six feet (1.8 meters), Australia and Germany say 1.5 meters, and France has one meter as its official guideline. The World Health Organization recommends people stay one meter apart.