The study needed approval from local authorities (City of Oslo and City of Bergen) to take place, which it did not get.

To investigate the impact of rapid antigen testing for Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2), the investigators plan to conduct a large trial to assess the impact of using rapid tests to screen people before participating at a mass gathering event, i.e. a music concert. Among participants who wish to attend and fulfill the inclusion criteria, half will be offered access to rapid testing and concert (provided the test is negative), and the other half will not. Allocation will be by randomisation. A week after the concert both groups will be tested by means of a standard PCR-test.

To investigate the impact of rapid SARS-CoV-2 antigen testing on the incidence of COVID-19, the investigators plan to conduct a large trial to assess the impact of using rapid tests to screen people before participating a mass gathering event, i.e. a music concert. The hypothesis is that screening by means of rapid testing eliminates any increase in risk of COVID-19 from attending a mass gathering event.

The investigators will recruit Individuals aged 18-45 years, who wish to attend a specific concert, have not received vaccination or had Covid-19 in the past six months, and are not in any risk group for severe disease. At recruitment, all participants (both concert and no-concert groups) will sign a consent form where they commit to using a contact tracing app, and to allowing the research group to use their data in the Norwegian Emergency Preparedness Register (BEREDT C19). They will also consent to having a COVID-19-test (PCR) conducted 6-8 days after the concert date.

After placing their payment, they will be randomised to be given access to a music concert (concert group), or not (no-concert group). Those who are randomised to the concert group will be tested for SARS-CoV-2 using a rapid antigen test, shortly before the concert. Those who test positive will be excluded from attending the concert and will immediately be offered a PCR-test.

All participants will be instructed to stay at home if they have symptoms of COVID-19 or are in quarantine. Participants who have symptoms or are quarantined at the time of the follow-up test will be offered a test through home visit by a mobile clinic.

Infection control measures will be applied to all concert participants in line with standards established by the sector, e.g. hand hygiene measures and a logistical system that seeks to minimise the risk of transmission during entry to the arena and exit after the concert

Inclusion Criteria:

• Aged 18-45 years
• Willingness to be randomised and to have a PCR-test taken a week after mass gathering event (both intervention and control groups)

Exclusion Criteria:

• Vaccinated for COVID-19
• Having tested positive for SARS-CoV-2 the last 6 months
• Risk factors for severe COVID-19

We will collect very limited IPD: Beyond outcome measures, the IPD will be age, sex. These data can be shared, at the individual level.

Until 31. July 2026.