In one scenario modeled by the scientists, the infection risk for participants and their contacts was around 70 times lower when health and safety instructions were followed, compared with what it could have been under pre-pandemic behavior.
“A concert or handball game with a strictly enforced safety protocol is safer than the participation in a big wedding,” said Michael Gekle, the dean of the medical department at the Martin Luther University of Halle-Wittenberg, who was involved in the research.
The scientists’ conclusions are based on an experiment that drew around 1,400 people to an indoor concert simulation in August, hosted in one of the country’s largest venues in the eastern German city of Leipzig.
The researchers from the Martin Luther University of Halle-Wittenberg, a public institution, used tracking devices to gather data on the movements and behavior of participants, all of whom had to test negative for the virus to be allowed to participate. Over the following two months, the data gathered during the day-long experiment in August was fed into a computer simulation to estimate the hypothetical spread of the coronavirus for varying safety protocols and infection rates.
Finding a balance between economic incentives to fill a venue as much as possible and safety constraints to limit the risks was the main goal of the experiment that looked at three scenarios.
In the first, participants — while still wearing masks — pretended that the pandemic did not exist, allowing the researchers to create a detailed computer simulation of a concert with no social distancing and with an auditorium at full capacity.
In the second scenario, organizers imposed light social distancing rules and reduced the number of participants. This scenario, the researchers said Thursday, would provide sufficient safety to hold indoor events up to an infection rate of 50 new cases per 100,000 people within a week. Germany deems regions that cross this threshold as risk areas.
Events could still be held with infection levels above that rate, the researchers found, but only if organizers were to follow stringent distancing, as modeled in a third scenario.
In all three scenarios, participants had assigned seats.
The researchers cautioned that participants’ safety largely depends on face masks and on indoor ventilation systems, which were both found to play a critical role in preventing infections.
Germany already approved a $580 million program last month to improve ventilation systems in museums, theaters and other spaces. As long as no effective vaccine has been widely distributed more funding for ventilation will be needed, said Stefan Moritz, who headed the experiment. “This pandemic won’t be over in a few months,” he said.
In the lead-up to the concert, the prospect of the experiment sparked hate mail and accusations that it would become a superspreader event, but the researchers said Thursday that the concert had resulted in no known infections.
The release of their findings Thursday came at a pivotal time in Germany, and one day after Chancellor Angela Merkel announced a month-long partial national lockdown this week saying health authorities have lost control of surging new infections. Some German federal states with relatively low infection levels so far — including Saxony-Anhalt, which partially funded the study — advocated for a less stringent approach.
Germany and other European countries had seen cases plummet in late spring, prompting optimism that a resumption of indoor events could be feasible. Saxony-Anhalt was set to reopen nightclubs Sunday, but those plans are now delayed for an indefinite period of time.
Hours before Merkel’s announcement Wednesday, thousands of event industry employees rallied in Berlin, calling for a resuscitation of their sector.
Their concerns are being shared by sports clubs. Many venues — including the Leipzig arena that was used for the experiment in August — are used both for concerts and sports competitions. The economic woes of the venue’s local handball club had triggered the study, amid concerns that the club would face bankruptcy unless it finds a way to host matches again.
Germany’s drop in new cases over the summer allowed the club and other sports associations to resume matches with a limited number of spectators, but organizers said they continued to face an existential dilemma, as events with only a fraction of spectators are often not profitable.
The findings presented Thursday could offer a compromise, the scientists behind the study hope. But with Germany about to enter another partial lockdown, their recommendations will have to wait.
The upcoming restrictions “will continue to apply,” said Armin Willingmann, the regional economy minister of Saxony-Anhalt, the state that partially funded the study. But the research findings, he said, could guide the state’s decisions “once things return to a degree of normality.”