Fig. 3From: Spatiotemporal distribution of COVID-19 during the first 7 months of the epidemic in VietnamClustering of COVID-19 cases from 23 January to 31 July 2020. a All phases of the outbreak, b Phase 1, c Phase 2 (Wave 1), and d Phase 4 (Wave 2). Red areas represent probable primary clusters of COVID-19 cases; light red areas represent secondary clusters of COVID-19 cases; and yellow areas represent tertiary clusters of COVID-19 casesBack to article page