How face masks have helped slow down the spread of coronavirus in Germany

Rachel Loxton
Rachel Loxton - [email protected]
How face masks have helped slow down the spread of coronavirus in Germany
A person wearing a face mask in Jena on April 6th. Photo: DPA

Face masks became mandatory in Germany at the end of April, but how effective are they? A new study highlighting the eastern city of Jena sheds some light on the controversial measure.


They have become synonymous with the coronavirus outbreak: whenever you’re travelling on a bus, train or shopping in a supermarket in Germany, you’ll find most people are wearing a covering over their mouth and nose.

But the introduction of face masks has been controversial, not only in Germany but across the world, with conflicting advice from experts particularly at the beginning of the pandemic.

Now a study by German researchers, which has gained international attention, has found mandatory face masks reduce the daily growth of reported coronavirus infections by around 40 percent.

And one German city was way ahead of the curve: the Thuringian university town of Jena, led the way by introducing a mask obligation (Maskenpflicht in German) on April 6th while other states across the country were hesitating.

Timo Mitze, Associate Professor at the University of Southern Denmark who is one of the authors study that hones on in how face Masks reduce Covid-19 in Germany, told The Local that Jena was a “pioneer”.

By the end of April, all German states brought in a rule saying people had to wear masks while travelling on public transport and in shops, some weeks after Jena.

READ ALSO: Jena becomes first German city to make wearing a face mask mandatory

Masks had 'positive effect' in Jena

So how effective has the mask obligation been in Jena?

“If we look at the number of Covid-19 cases in Jena, masks seem to have a positive effect,” Mitze said in an evaluation of the study.


“The number of registered new infections fell to almost zero in the days after masks were introduced. But was this really due to the introduction of masks and a publicly visible campaign?"

Researchers came up against limitations.

"Unfortunately, there is no second Jena in Germany, which would allow us to measure the spread of Covid-19 if face masks had not been introduced under otherwise identical conditions," said Mitze.

The authors instead used a synthetic control method to compare Jena to similar regions in Germany (such as Rostock, Darmstadt, and Trier) that did not introduce the mask obligation until later. 

According to their calculations, "there is a significant gap between the number of cases in Jena and the comparison group without compulsory masks". 

Twenty days after the introduction of compulsory masks in Jena, the total number of Covid-19 cases registered there had only risen from 142 to 158, whereas in the comparison model it had risen from 143 to 205. This corresponds to a reduction in the number of cases in Jena by around 23 percent.

The drop in Jena was greatest – more than 50 percent – for the age group of 60 and above, indicating that masks are useful for risk groups.

Face masks on statues in Jena. Photo: DPA

In a second set-up, the researchers investigated the development of the number of cases in the cities and districts that introduced compulsory masks before or on April 22nd, including Nordhausen in Thuringia, Rottweil in Baden-Württemberg, the Main-Kinzig district in Hesse, and Wolfsburg in Lower Saxony. 

The study authors – Mitze, Reinhold Kosfeld, Johannes Rode and Klaus Wälde – compared these regions with those that introduced masks on April 27th or later. 

They found smaller effects than in the Jena case study. However the average reduction in case numbers “remains significant and sizeable”, say the authors.

A total of 10 days after the introduction of masks, the decrease in the cumulative cases is between 2.3 and 4.2 percent.

Mitze said that taking all of the research into account, the daily growth rate of Covid-19 cases in Germany dropped by about 40 percent. 

“The introduction of mandatory face masks has slowed down the spread of Covid-19 in Germany,” he said. “This result agrees with the findings of epidemiologists and virologists who explain that face coverings limit airflow when speaking, thereby reducing the transmission of infectious particles.”

READ ALSO: Why a row has broken out in Germany over face masks

So why were masks so successful in Jena?

Mitze told The Local it could be down to more than one factor, such as the social aspect – not only the medical effect of wearing a face covering.

“There is the medical effect when you wear the mask – the transmission channels are blocked to a certain extent," said Mitze. "Then on top of that there is this social aspect of being cautious (when there is a mask obligation in place).”

Mitze said Jena’s campaign “Jena zeigt Maske” (Jena shows mask), which was put in place a week before the introduction of the rule, may have helped locals become familiar with the restriction. 

“Jena is a pioneer city,” said Mitze. “So maybe the response to face masks there was particularly strong."

This could all have contributed to people in Jena behaving much more cautiously (for example observing hygiene and distance regulations), while taking the measure seriously and sticking to the rules.

Should masks remain in Germany even when Covid infection numbers drop?

A debate was sparked in Germany this week over whether the mask obligation should be partially scrapped to support businesses.


Mecklenburg-Western Pomerania economy minister Harry Glawe spoke out in favour of getting rid of the mask requirement to help the pandemic-hit retail trade. However, states decided to keep the rule in place.

READ ALSO: Face masks to remain mandatory in shops across Germany

According to Mitze, the results of the study suggest that Germany’s face mask requirement is a “cost effective, less economically harmful, and democracy-compatible containment measure for Covid-19”, especially compared to other measures such as closing schools, shopping centres and restaurants. 

However, he understands why the retail sector, for example, would be keen to get rid of the mask requirement. 

Mitze said: “My opinion is: comparing it to the risk of another lockdown with limiting personal freedoms of moving around and closing down the economy, then – relatively – the costs of wearing face masks are low."

Tobias Kurth, professor of public health and epidemiology at the Charité in Berlin, said wearing a face mask "helps to reduce the likelihood of coronavirus spread".

"This is also true for Germany," he added. "It is key that we keep on wearing face masks in public transportation or public indoor places and yes, this should be mandatory.

"This is small but effective way to help to control the pandemic. We should keep on doing this until there are other effective ways to control the pandemic, such as a vaccination that is effective and available."

'Relatively mild remedy'

Politicians, scientists and researchers have also warned against removing the requirement too quickly, just as people have got used to them.

Mitze said people were very wary of wearing masks initially “but now people seem to have adjusted to this”.

“If you relax a measure, how easy can you reintroduce it back again?” he said. However, he acknowledged for some groups, such as people with difficulties hearing, face masks can be trickier.

A man wearing a mask in Berlin. Photo: DPA

Mitze said innovations, such as transparent face masks and other new ways of covering the face, could help break down these barriers.

These comments mirror Federal Health Minister Jens Spahn who on Thursday warned against relaxing the mask requirement too early.

READ ALSO: 'They're warm and you can't breathe well': Germans don face masks for first time

In order to reduce the risk, there is an obligation to wear masks in certain public settings, said the Christian Democrat (CDU) politician. In his view, he said: "It's better to have it (the restriction) lifted three weeks too late than three weeks too early".

He said that wearing masks was not always pleasant, but that it was a "relatively mild remedy" compared to other restrictions. This is particularly important when distances cannot be maintained, such as on public transport or when shopping, Spahn said.


While there is no vaccine or treatment and the risk of second wave remains very real, evidence suggests masks are a useful tool.

“What is the alternative?" said Mitze. "Opening the economy now and risking a much steeper second wave? Second round costs may even be much higher if one relaxes face masks too early."



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