Before revision:  This paper proposes a generalized Markov-Switching approach, the SUIHR model, designed to study border control policies and contact tracing against COVID-19 in a period where countries start to re-open.
After revision:  This paper proposes a generalized Markov-Switching approach, the need to revert back to more restrictive life styles or to rely on herd immunity. When the base reproduction number of COVID-19 in a period where countries start to re-open.