Nobody Was Infected During The Primavera Sound-CoV Study
Last December, I mentioned an experimental study done in Barcelona, Spain, which attempted to evaluate the effectiveness of same-day coronavirus screening with antigen tests before a long concert.
During this Primavera Sound-CoV, 1,000 people received a rapid antigen test, which can produce results in 15 minutes, using a nasal or throat swab. Around 500 of them attended a 5-hour music festival inside Barcelona’s Sala Apolo, where social distancing was not reinforced, and the other 500 served as the control group. The goal was to evaluate the effectiveness of this rapid testing before a concert based on the hypothesis that a live concert performed under safe conditions would not be associated with an increased risk of SARS-CoV-2 infections. The concert included 4 performances: 2 Dj sessions and 2 live music with groups, for 5 hours overall.
The results are in. After a week, all participants were tested again for SARS-CoV-2, and they found that ‘none of the 463 participants in the experimental group was infected with SARS-CoV-2 (incidence 0%; 95% credibility intervals: 0% -0.7%.’ Meanwhile, and ironically, 2 of 496 participants were infected in the control group composed of the people who did not have access to the concert (incidence 0.4%; credibility intervals 95%: 0.1% -0.8%). The two infected people in the control group were detected by rt-PCR and by antigen test.
This is good news, the study shows that COVID-19 can be detected by a rapid antigens test done on the same day. At least it worked this time, as there were no people contaminated inside the concert hall.
Does it mean we can have concerts again and pretend we are back to normal? Not so fast, 500 people is a significant number of people to test, and I cannot imagine doing that every time there is a show. Not only this would require a lot of time but also a significant increase in the price. This specific study was made possible thanks to Fight AIDS and Infectious Diseases Foundation and the University Hospital Germans Trias i Pujol in Badalona (Barcelona), and so every live event would have to find the same kind of prestigious sponsors. Then, there apparently were zero false-negative tests in the study, which is good news but how can we be sure it would always be the case?
There is a wide range of accuracy for these antibody tests. According to Webmd, the ability to correctly identify people with the disease ranged from 61% to 87% back in September, and according to this study, out of 807 people receiving a negative test result, up to 17 (2%) of those people could have COVID-19 (known as a false-negative result). And this would be a real problem for large events.
The Primavera Sound-CoV study gives us some hope but I am still skeptical this will be used to bring back large music festivals this spring or summer. It could happen by the end of the summer or fall when more people are vaccinated, but concerts will return small before they can be big and large again. We just have to be patient.