SARS-CoV-2 Infection Risk Imposed by Fully-vaccinated Air Travelers Attending an Island-confined Quarantine System Enabling Tourism During the Pandemic: A Retrospective Cohort Study

Despite the relatively low risk of SARS-CoV-2 infection, a risk of breakthrough cases remained with certain vaccines. Given the high proportion of asymptomatic cases, quarantine and intermittent testing should be implemented. The mandatory quarantine system proved effective in managing positive cases without necessitating a complete shutdown of travel. Implementing an island quarantine could be a viable strategy for reintroducing travel and tourism during a future COVID-19 outbreak or a new pandemic.