Indoor concerts pose a “low to very low” risk of attendees contracting COVID-19 so long as measures are adhered to by both the venue and the fans, according to a German study.

The experiment, which is part of a project called Restart-19, run by the University Medical Center in the German city of Halle (Saale), found that transmission is “low” so long as attendees follow correct hygiene procedures, the venue limits capacity and maintains good ventilation.

In August, more than 1,400 concertgoers in Germany were enlisted to attend a Tim Bendzko (pictured) concert in Leipzig and were equipped with masks, tracking devices that transmit a signal at five-second intervals and bottles of fluorescent disinfectant. The volunteers were also pre-tested for COVID-19 and had their temperatures taken.

Dr. Stefan Moritz of University Medicine Halle (Saale), who led the study, said: “The results are consistent with our hypothesis that the contacts that do occur at an event do not involve all participants. Therefore, events could also take place under specific conditions during a pandemic.

“The most important finding for us was understanding how crucial it is to have good ventilation technology. This is key to lowering the risk of infection.”

The findings on ventilation, which was found to be a crucial factor in limiting the transmission of COVID-19, resulted from flow simulations conducted in conjunction with an engineering company. Moritz explained: “Together with this engineering company, we recreated the entire Quarterback Immobilien Arena as a computer model and divided it into small cubes. We then simulated how different ventilation scenarios affected the distribution of the aerosol particles.”

The 12,000-capacity Leipzig concert hall, where the experiment took place, was asked to model three different scenarios with changes to the number of entrance points and capacity.

The first saw the volunteers entering through two main doors before taking their seats, while the second “optimised” scenario saw the crowd enter through eight entrances to facilitate less mingling, and every second seat on the stands was blocked.

In the third, only 2,000 spectators were allowed to enter the venue and be seated at a 1.5m distance from each other.

Dr. Michael Gekle, dean of the Faculty of Medicine in Halle, said: “The concept of the project was compelling, and we would like to thank all of the participants who took part. They generated the data which we can use to make science-based political decisions. They generated the data that will also benefit others all over Germany and even around the world who would like to resume going to indoor concerts or sporting matches.”

The Minister of Science, Professor Armin Willingmann, added: “The corona pandemic is currently intensifying throughout Germany. This reality makes what we learn from ‘RESTART-19’ all the more valuable. The events industry, in particular, must be equipped with the knowledge and strategies it needs to be able to responsibly organise concerts, festivals and trade fairs despite Corona.”

Image: Raimond Spekking / CC BY-SA 4.0 / Edited for size