New Delhi: In a unique study, Spanish researchers conducted a live music concert in a well-ventilated hall with over 460 people to show that such events can take place during the Covid-19 pandemic with proper safety measures.
The study, published in the The Lancet Infectious Diseases journal, is a first-of-its-kind research that assesses the impact of comprehensive Covid safety measures at an indoor live music concert event.
The safety precautions at the event included same-day screening of attendees using lateral flow or rapid antigen tests, which give results within 30 minutes, before entry, coupled with mandatory N95 mask wearing, enhanced ventilation and crowd control. There was also no recommendation for physical distancing at the event.
The study was conducted in Spain’s Barcelona on 12 December 2020. At the time, prevalence of infections in the region was low, with just about 221 cases being reported for 1,00,000 people.
Furthermore, there were local travel restrictions in place, indoor meetings were limited to six people, and Covid-19 vaccines were not yet available in the country.
“Our study provides early evidence that indoor music events can take place without raising the risk of SARS-CoV-2 transmission when comprehensive safety measures are in place, but it is important that our findings are considered in light of the situation in Spain at the time – when cases were not high and many restrictions were in place,” Josep Llibre, the study’s lead author, from the Germans Trias i Pujol University Hospital, Spain, said in a statement.
“As a result, our study does not necessarily mean that all mass events are safe,” Llibre cautioned.
Ventilation, antigen tests, N95 masks used in concert
In May last year, the US Centers for Disease Control (CDC) found such a superspreader event at a choir practice in Washington.
Around 61 people met for 2.5 hours on 10 March to sing and eat. The group included one symptomatic Covid patient. By 17 March, 53 of the attendees were ill, three had to be hospitalised and two had died.
However, since then, the scientific understanding of how the virus spreads has improved. Scientists now know that coronavirus is much more likely to spread through aerosols we breathe in, rather than the surfaces we touch.
Research also shows that ventilation and wearing masks is much more important than surface cleaning and physical distancing in indoor settings to prevent transmission.
Therefore, the Spanish study sought to put this research into praxis with their concert.
Around 1,000 people aged between 18 and 59 years were recruited to take part in the study. People who had previously tested positive for Covid-19 or been in contact with a positive case in the previous two weeks, had comorbidities or were living with older people at the time of the study were excluded.
All participants tested negative on a lateral flow test conducted by a healthcare professional. Lateral flow tests, also known as Covid-19 rapid diagnostic tests or rapid antigen tests, offer a means of quickly testing for SARS-CoV-2.
As many as 465 participants were randomly allocated to attend the music event while 495 were asked to return home to their regular lives.
The same swab samples from each participant were sent to a laboratory for confirmatory Covid-19 testing.
All participants, including those who did not attend the event, were visited by a healthcare professional eight days after the event for collection of a second swab from the back of the nose and throat for another Covid-19 test.
Safety measures for indoor concert
The indoor event took place at a venue, which has a capacity of around 900 people. In addition to testing, all attendees had their temperature monitored before being allowed entry to the venue and were given an N95 face mask, which had to be worn at all times inside the venue.
Hand sanitisers were provided at multiple points, the venue was well ventilated — all access and exit doors remained open throughout to allow fresh air to circulate — and the temperature was controlled so that attendees could comfortably wear their masks.
The event lasted five hours and the attendees spent an average of two hours and 40 minutes inside the venue. There were two DJ performances and two live music acts. Drinks, including alcohol, were served in a separate bar room and there was a smoking area outside with controlled capacity and physical distancing.
Everyone who took part in the study was required to install two smartphone apps — one contact tracing app to capture close contacts of people who may have become infected during the concert and a separate app to receive confidential test results.
Participants also used this second app to complete health questionnaires before and 10 days after the event along with a satisfaction survey for those who attended the event.
None of the people who attended the event tested positive for Covid-19 eight days after the event. In comparison, two people from the group who did not attend the event contracted the virus.
Overall, the findings showed that there was no increased transmission of SARS-CoV-2 associated with event attendance.
“Mass gatherings are associated with a high risk of spreading the SARS-CoV-2 virus and the cancellation of large events has played an important role in bringing the COVID-19 pandemic under control,” said Boris Revollo, one of the study’s co-authors from the Germans Trias i Pujol University Hospital in Spain, in a statement.
“However, these cancellations have resulted in substantial economic losses, estimated in the region of €5.5 billion in Spain alone,” Revollo said.
“As societies look toward the possibility of safely resuming cultural activities, lateral flow tests, which can deliver results within 30 minutes and be taken on site, have been proposed as a means of screening people on entry to enable large events to take place,” he added.