The risk of catching COVID-19 decreases by 80% when you are at least one meter away from others and drops even more by half when you are at a distance of two meters, according to a major Canadian study. .
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According to this survey published Monday in the journal The Lancet and funded by the World Health Organization (WHO), the risk of being infected is on average 12.8% near a person infected with COVID-19 if the rules of social distancing.
With a distance of one meter or more, this risk drops to 2.6%, a relative drop of 80%. In addition, for each additional meter of distance, the risk of transmission would be cut in half.
These results were obtained following a major scientific review which identified 172 studies from 16 countries published for several years on three respiratory infections: COVID-19, but also SARS and MERS, these the latter two being older and therefore better documented.
This meta-analysis also found that wearing a mask and eye protection greatly reduces the risk of virus transmission.
In this sea of data, nine studies were used for the results regarding physical distance.
“Our main finding is that a physical distance of about a meter or more probably provides broad protection against infection,” said the article’s lead author and McMaster University professor Holger Schünemann in an interview. with The newspaper.
These results fuel the debate about physical distance in places of the world where it is two meters (except between members of the same household), as is the case in Quebec.
Several countries and the WHO, however, are content to recommend a distance of at least one meter.
Schünemann does not want to settle this debate, but his work does not contradict the two-meter rule. On the contrary, “the available evidence suggests that two meters may be more effective than one meter,” he said.
Question of context
The scientist also insists that everything is a question of context and that one should not believe that the estimates of his team apply to all situations.
Factors such as location (open or closed), length of exposure, or viral load received greatly vary the risk of getting someone else’s COVID-19.
Invited to comment on this study, Quebec epidemiologist Caroline Quach-Thanh believes that we must continue to advocate two meters in Quebec. “When we say two meters, we know very well that people underestimate all the time, so we tend to get crowded at a meter, a meter and a half. The point of aiming for two meters is that the risk is actually half that, “she notes.
Uneven rules around the world
► At least 2 m:
- United States
- United Kingdom
► At least 1.5 m:
► At least 1 m:
In schools, the rules for social distancing are generally the same as in society and therefore also vary from country to country.