At 3 m distance, an unvaccinated person without a mask is 90% sure of catching Covid-19 in 5 minutes!

Two people discuss without masks, but keeping their distance. One of them is infected with SARS-CoV-2. In 9 out of 10 cases, his interlocutor will also be infected after only five minutes. This is the conclusion of a study of Max Planck Institute for Dynamics and Self-Organization who calculated the maximum risk of being infected in several situations involving two people face to face, including one infected, who gate a mask or not.

Eberhard Bodenschatz, the director of Max Planck Institute for Dynamics and Self-Organization confesses it, he did not expect that“At a distance of several meters, it would take such a short time for the infectious dose to be inhaled from the breath of a carrier of the virus.” Indeed, in one of the scenarios tested by him and his team, where an infected person talks with an uninfected person while respecting a distance of three meters but without a mask, it only takes five minutes for the coronavirus goes from one to the other.

Masks, an effective barrier against the coronavirus

Three other scenarios were tested: the two interlocutors wear a surgical mask or FFP2, and the interlocutor infected with SARS-CoV-2 does not wear any but his opposite does (surgical or FFP2). Another detail, the infected person is talkative. When both people wear a surgical mask, the maximum risk of becoming infected with the coronavirus is 30% after an hour. Under the same conditions, this maximum risk is only 0.4% if both people wear an FFP2 mask. If the uninfected person is the only one protected by a surgical mask and placed about 1.5 meters apart, the maximum risk of becoming infected is 90% after 30 minutes of discussion. And 20% after one hour for an FFP2 mask. The way the mask is worn also affects the likelihood of being infected with the Covid-19. If the masks are ill-fitting on the side of the face or at the level of the nose, the risk of being infected increases by 4%. If the masks are well adjusted, the risk of becoming infected is about 10% after 20 minutes.

Lower risk in real conditions

” In real life, the true likelihood of infection is certainly 10 to 100 times lower », Explains Eberhard Bodenschatz. Indeed, to carry out their experiments, scientists had to make choices that do not necessarily reflect real situations. For example, difficult to estimate the amount ofair that escapes the mask and hits another person in every situation. If the theoretical maximum risk calculated here is already low in scenarios including a mask, it must be even lower in real life. ” This is why it is so important that people wear a mask during the pandemic », Concludes Gholamhossein Bagheri, first author of the study.