An ambitious German study on the risk of transmitting the coronavirus at major sporting and cultural events attracted international attention. The organizers have now revealed their findings.
It could feel like the wrong timing to discuss how large arena events should take place again. The number of people infected with COVID-19 is dramatically increasing, and all large-scale events have been cancelled again in Germany, as Chancellor Angela Merkel has just announced an emergency one-month partial lockdown to curb the spread of the virus in the country.
But for professor Michael Gekle, dean of the University Medicine Halle, "We couldn't have had a better dramatic structure," he said at the opening of the press conference to reveal the results of an experiment that attracted international attention, "from media in South Korea, to the BBC, to the Washington Post," as he pointed out.
For the study, titled "RESTART-19 study on the transmission risk of COVID-19 at major sporting and cultural events," the organizers held a series of concert simulations in August in the Leipzig Arena.
It involved nearly 2,000 volunteers who had previously been tested negative for COVID-19. They had to wear throughout the event a FFP2 protective mask, which blocks respiratory droplets through which the disease could be transmitted, as well as a so-called contact tracer, a device that tracked their movements and measured whenever and for how long two people were in close contact.
The participants then followed three different scenarios, with varying admission and seating plans. The first one had everyone seated next to each other, as was typical before the pandemic, and the two others left a varying number of empty seats between the concert-goers.
Beyond measuring the number of close contacts, the study also included a computer simulation, based on the science of "computation fluids dynamics."
Professor Stefan Moritz, director of the study, explained that the arena and its current ventilation system was digitally recreated, and 24 infected participants were included in the virtual model.
The simulation was then also tested with an alternative ventilation model, which however turned out to be less effective than the original one. It still allowed the scientists to compare how aerosols spread with a "good" versus a "bad" aeration system.
The data on the number of aerosol contacts determined by the computer simulation was combined with the results of the first part of the study — the number of close contacts of the participants during the three varying scenarios.
Based on the study's results, professor Stefan Moritz provided a series of recommendations to avoid spreading the virus and nevertheless keep holding live events in arenas.
For one, the scientists advise against holding full-capacity events in arenas. The event's hygiene concept must include reducing the number of attendants.
The other recommendation is to hold seated instead of standing concerts. "Seated events have the advantage of setting fixed contacts in the arena and they also determine the distance between the concertgoers," said Moritz.
A third recommendation is to increase the number of admission points, as close and longer contacts with others occur while waiting to enter and leave the arena.
Another point recommended by the study's director is to impose a mask requirement in the arena for the entire concert. In a poll, the vast majority of the participants of the study said they would be ready to wear a cloth mask throughout an event, but not that many could imagine wearing the FFP2 mask and enjoy a concert. The cloth mask would be sufficient, according to the study's organizers.
Additionally, to avoid multiplying virus-spreading situations, it should only be allowed to eat and drink at the concert-goer's seat, said Moritz.
The event organizers should also plan "hygiene stewards," people hired to ensure such rules are respected. Moritz pointed out that this is an aspect that would distinguish arena events from private large events, such as weddings.
Finally, an adequate ventilation system must be available in the arena. An evaluation system must be developed to determine if this is the case, and the study organizers also recommend the development of a governmental investment program to allow better aeration systems to be installed in large halls.
For fans of arena concerts, such a list of requirements feels miles away from the pre-coronavirus electrifying experience they are used to.
But for professor Gekle, having scientific data to deal with the complexity of the current situation is better than improvising based on "beliefs."
As he also pointed out, the pandemic is set to last for several months, as the Robert Koch Institute, Germany's national institute for disease control, just announced that a vaccine for the entire population should not be expected before 2022.
For Gekle, one thing should be clear until that is achieved: "No culture is not a solution."