Table 2.

Time periods considered for wild-type SARS-CoV-2 transmission during 2020 and Delta variant transmission during 2021

SARS-CoV-2 lineage	Time period	Description
Wild-type	Jan 18–Feb 29, 2020	Transmission driven by travellers arriving from Wuhan
	Mar 1–Apr 6, 2020	Returning travellers from countries with ongoing outbreaks
	Apr 7–Jun 18, 2020	Increased reopening of national borders
	Jun 19–Jul 12, 2020	Resumption of more local activities
	Jul 13–Dec 31, 2020	Increased reopening of national borders
Delta variant	Apr 1–May 12, 2021	Transmission driven mainly by travellers arriving from India
	May 13–Jun 20, 2021	Tightening of outbreak control measures before relaxation of measures in mid-June
	Jul 1–Jul 17, 2021	Nightclub and fishery port outbreak clusters
	Jul 18–Aug 18, 2021	Tightening of outbreak control measures