The researchers looked at 172 observation studies in 16 countries and six continents, including health and community settings. They did not look at randomized controlled trials, considered the gold standard, but it was almost impossible to apply to study the transmission of infections in humans.

Researchers at universities around the world analyzed studies from the epidemics of Covid-19, the severe acute respiratory syndrome virus and the Middle East respiratory syndrome virus (MERS), from the same virus family.

‘The big step forward’

The results of the research support the physical distance policy of researchers at least 1 meter (3.3 feet) and 2 meters (6.6 feet) or more if possible. The information can also be used to inform models that predict the spread of the disease and to assist contact monitoring programs by the research team led by Holger Schünemann of McMaster University in Canada.

Trish Greenhalgh, a primary care professor at the University of Oxford, who was not involved in the research, said that while all these results were uncertain, the overwhelming message was that physical measures were effective in preventing Covid-19.

“This is a big step forward in our knowledge, because previous meta-analyzes were based primarily on the prevention of influenza and other diseases, which does not behave the same as the Covid-19 virus,” he told the Scientific Media Center. London.

“The evidence seems to support the measures in all three questions. For example, staying 1 meter away from other people seems to have reduced your chance of catching Covid-19 by 80%. Wearing a mask or face covering seems to be decreasing. It seems to be down to. “

WHO spokesperson Tarik Jašarević said the international healthcare organization’s advice on wearing a mask is in the process of updating, with a likely change to be announced this week.

Changes are “likely to touch the best ingredients to make homemade” “The masks are based on the latest data from the United States,” he said to CNN via email.

“WHO continued to focus on the use of masks with evidence that it can limit contamination, as in healthcare settings. In fact, new guidance can expand their use in these settings.”

Next steps for government leaders

Linda Bauld, professor of public health at the University of Edinburgh, now the key question was how governments and the public should interpret these results.

“The first and probably the most useful finding is that physical distance is important. There were many complaints that the 2-meter guidance in the UK was excessive because it was more than other countries,” he told the Science Media Center.

“However, this review supports this. Maintaining this distance will likely reduce the risk compared to 1 meter. Therefore, this is the distance retailers and employers should use to reopen more facilities and businesses in the future, if possible.”

Bauld added that while the evidence on face masks was low, making it difficult for governments to make them mandatory, he added that the review asked leaders to wear face coverings in public transport, shops and other areas. He said indoors even if there are physical distances.

For healthcare workers, the study found that N95 masks and other respirator-type masks can provide more protection from viral transmission than surgical masks or multi-layered cotton or gauze.

However, the review did not look at the effects of wearing a mask to protect other people from Oxford’s Greenhalgh. He said that the general public should wear a respirator mask or a standard surgical mask, leaving their respirators with respirators.

Even when used and combined properly, removal, masks and eye protection do not provide complete protection, operation is highlighted and basic measures such as hand washing are required to reduce contamination.