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Thursday, October 22, 2020
By Klaus Wedekind
The President of the Medical Association, Reinhardt, fights against everyday masks with “Lanz” and rekindles the discussion about its benefits. It will never end soon, because in this case it is not easy to provide scientific evidence.
For the World Health Organization (WHO), masks play a “key role” in the fight against the spread of Covid-19. They saved lives, it says on the relevant information page. At today’s press conference, the RKI came out in favor of the constant use of masks in areas where people gather, especially indoors.
Virologist Christian Drosten said on his NDR podcast that the masks could not completely stop the aerosols responsible for the transmission of the coronavirus, but people who wear them would not become infected as quickly. But not all scientists are so convinced of the benefits of masks in the fight against Covid-19. The director of the German Medical Association, Klaus Reinhardt, is one of them.
“No scientific evidence”
Reinhardt criticized the everyday masks in “Lanz.” “In local traffic and where the going gets tough,” you can still accept the masks. But he was not convinced of their effect and there was no scientific evidence that they were helpful, he said. “Especially not in self-protection and probably very little in protecting others.”
The president of the German Medical Association is not alone in his assessment. A group of scientists write in a thesis article that “the effectiveness of the protection measures currently recommended by the WHO and common internationally, including the use of masks”, has not yet been examined in a randomized study.
They refer to a Canadian commissioned by the WHO WHO meta-analysisThey concluded that protecting the mouth and nose can reduce the risk of infection by 85 percent. However, only one of the 172 studies evaluated was directly related to Sars-CoV-2, the scientists criticize. The other work is on the other corona viruses. Sars and Mers been done.
Difficult risk assessment
However, they consider more problematic that when evaluating where the masks should be used, the so-called basic risk is not taken into account. This is the risk of infection that you generally have in a certain situation.
The authors of the meta-analysis also point to the problem. Using Norway as an example, they estimate that a total of 200,000 people have to wear a mask to avoid a new infection each week. In this way, a 40 percent reduction in relative risk can be achieved. The situation is different with hospital employees, for example. Here, the risk of infection for one in two professionals in the medical field can be reduced by 40 percent if everyone in this environment wears a mask.
Requesting is easier than delivering
German scientists call for randomized studies on the effectiveness of masks. However, this is easier said than done. Because that means that half of the test subjects cannot wear masks. It is not known how high the risk of infection is; this must first be proven by such studies.
As for the scientific evidence requirement, it could also be said that the lack of evidence does not mean that the masks do not work. And how quickly you can go wrong if you let go too far with Covid-19 can also be seen in the German scientists’ thesis paper, which is dated August 30. In it they write that in November the daily registration numbers of up to more than 3000 “are not surprising” and that politicians should not speak of a second wave. Today, the RKI counted more than 11,000 new infections.
Is a critical study being boycotted?
Still, researchers are right to ask for better scientific studies on the effectiveness of masks. In fact, a randomized study has already been carried out in Denmark, in which half of 6,000 participants wore a mask at work. However, according to the description, it should be found out if the masks protect the user from infections. Scientists are apparently less interested in investigating the effects of masks against the spread of the virus.
According to the scientific journal “Nature”, one of the lead scientists, Thomas Lars Benfield, says his team is not yet ready to share the results. One is circulating on Twitter Email Benfields, in which he writes that the results of the study can be seen if a specialized journal has the courage to publish them. The Danish daily “Berlingske” also reported this.
This seems suspicious, but is due more to the fact that many studies are awaiting publication. Danish study lead scientist Henning Bundgaard told “BT” newspaper that it was also customary to wait months or years for a publication. Also, never send studies to multiple journals at the same time, but to one at a time. “It’s a difficult and expensive process for journals to do a study,” he says.
New study shows effectiveness
A recently published Canadian study is not based on randomized results, but it is still very informative. Scientists at Simon Fraser University in Burnaby have looked at different developments in Canadian provinces after the introduction of a nationwide mask requirement. The provinces implemented them at different speeds, some taking up to two months.
A comparison of the different numbers of infections showed that the masks reduced weekly cases by between 25 and 46 percent in the first weeks after the introduction of the obligation. The Canadian study thus confirms, among other things, the findings that scientists have obtained using the example of Jena, which introduced the mask requirement much earlier than other comparable cities.
Much remains to be clarified
However, debate still needs to be done, and not just because the exact protective effect of masks has yet to be scientifically established. It is also necessary to clarify which mouth and nose covers provide effective protection and what effects handling errors can have.
At least when it comes to the effectiveness of some everyday masks, doubts are more than appropriate. The WHO recommends three-layer masks with filter cloth for a reason. Most community masks probably won’t meet this requirement. Much also depends on the material used. Fine mesh fabrics filter much better than coarse mesh. According to a US study, surgical masks are the best way to keep particles away from everyday masks, while scarves have little effect.
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