The objective is to demonstrate if there is no increase in the risk of Sars-Cov-2 salivary carriage 7 days after a concert in the group participating in the event compared to a non participating group who stayed at home.

The hypothesis is that a systematic screening of Sars-Cov-2 within the 3 days before the event allows to control the risk of transmission and prevent cluster of transmission during the concert.

Before inclusion, the participants will be able to pre-register to the event via a website. They will get an appointment for an inclusion visit at the Accor Arena (Paris Bercy, France).

During 3 days (from D-3 to D-1), participants with a registration will come to the Accor Arena to have a rapid Sars-Cov-2 antigen test (results in 15 min).

If the test is positive, the participant will be contacted and managed by the medical team in charge of the national strategy for positives cases.

People with a negative test will be included and randomized :

• Two kits with tube for collecting saliva samples (for D0 and D7) will be given to each participant at this visit
• People randomized in the experimental group will receive their concert ticket at a later date.
• At Day 0, people randomized in the experimental group, will come to the Accor Arena with their ticket to participate in the concert. At the entrance, they should give their D0 saliva sampling kit. The people randomized in the control group will stay at home and will send their D0 saliva sample by post mail.
• At Day 7 (±1 day) all the participants must return their D7 saliva sampling kit via post mail

Inclusion Criteria:

• aged between 18 and 45 years old
• lack of symptoms or no contact with people with Covid-19 in the last two weeks
• negative antigenic test to Covid-19 in the 3 days before the experiment
• people who declared to have no risk factor to severe form of Covid-19
• people who declared not to live in the same place as someone with these risk factors
• people residing in Ile-de-France area

Exclusion Criteria:

• positive test to Sars-Cov-2 within 3 days before the concert
• people with clinical signs suggesting infectious respiratory disease
• people with severe Covid-19 risk factor
• people living with someone having severe covid-19 risk factor
• not affiliated to social security
• people who cannot remain standing for the time of the experimentation (about 5 hours)
• person under tutorship or curatorship
• pregnant women or not having effective contraception method
• breastfeeding women