Using rapid tests for SARS-CoV-2 to screen participants before mass gathering events is a proposed strategy for conducting events at persistently high infection incidence. The tests' ability to detect infectious participants is uncertain since assessments of test properties (sensitivity / specificity) are based on comparisons with PCR test results. Although a PCR test is highly sensitivte with regard to the presence of virus particles, the test does not provide a clear answer as to whether a person is contagious, e.g. because those who have been infected may have positive test results also when they are no longer contagious. To evaluate whether rapid testing is an effective intervention to prevent viral spread, comparative studies of rapid testing versus non-rapid testing are needed. Randomisation of participants ensures comparable groups, enabling us to assess whether differences in infection levels are due to to differences exposure to the interventions (rapid tests and participation in events). The standard method for measuring COVID-19 prevalence in groups is to perform PCR testing of all participants, which is wha we plan to do.