Leipzig, Germany (December 3, 2020)—According to the results of Restart-19, an experiment in Germany, indoor sports and cultural events including music concerts could return soon—under the right conditions. The test was conducted by a team from Leipzig’s Halle University, who report that “seated indoor events, when conducted under hygiene precautions and with adequate ventilation, have small effects on the spread of COVID-19.”
The study was held in August at an 8,000-seat arena in Leipzig, where popular German singer Tim Bendzko and his band played to about 1,200 people. The 10-hour event was designed to test the potential spread of the novel coronavirus through contact and exposure to aerosol droplets. The results, published in November, have not been peer reviewed.
The team, led by Dr. Stefan Moritz, head of the university’s clinical infectious diseases department, designed the event to study three different scenarios: a pre-pandemic concert with no safety measures, an event with some social distancing and a hygiene regimen, and a reduced crowd with concertgoers positioned about six feet apart. The experiment included various entrance and exit scenarios, bathroom breaks and simulated food and drink purchasing.
Attendees, who were required to have tested negative for COVID-19 no more than 48 hours prior to the event, had their temperatures taken on arrival, were given N95 face masks and were provided with tracking devices to measure their social distancing. Fluorescent disinfectants were applied to their hands so that the team could study which surfaces concertgoers touched the most. The results suggest that good ventilation, strict hygiene protocols, limited capacities and social distancing can minimize the potential for spreading the virus. Computer modeling of larger audiences—the organizers had hoped for 4,000 volunteers—showed similar results.
Adequate ventilation appears to be key to safely hosting mass gatherings of people in indoor venues. Researchers found that the density of viruses in aerosols was decreased through regular air circulation. “We knew that ventilation was important, but we didn’t expect it to be that important,” the team’s Dr. Michael Gekle told The New York Times.
The report stresses the importance of good ventilation: “[I]n scenarios with physical distancing, the resulting contact numbers are rather low and the effective risk depends primarily on the adequacy of the ventilation. Thus, under hygiene protocols and good ventilation, even a substantial number of indoor MGEs [mass gathering events] has only minimal effects on the overall number of infections in the population. However, poor ventilation systems can lead to a considerably higher rate of aerosol expositions and can thereby result in a high number of infections.”
In the experiment, contact was generally less than 15 minutes between participants. Prolonged contact of several minutes was observed during the breaks between performances and during entry to the venue. In the pre-pandemic scenario, contacts tended to accumulate over the duration of the event.
Commenting to The New York Times, Emily Eavis, co-organizer of the Glastonbury Festival, said, “Obviously if masks are going to work for larger gigs, then that’s big progress.” The Leipzig experiment focused on seated events, where social distancing can be managed. Outdoor festivals, though well ventilated, are likely to remain riskier ventures until vaccine use is sufficiently widespread.
The organizers of Spain’s Primavera Sound festival are reportedly helping to conduct research into the efficacy of rapid COVID-19 testing as a method for screening music fans. In the United States, Ticketmaster has floated a plan to vet concertgoers once they have purchased tickets. The scheme would involve third-party testing and vaccine distribution providers and health information reporting companies. The U.S. Food and Drug Administration has not yet approved any such digital screening services.