Spatiotemporal Evolution of SARS-CoV-2 Alpha and Delta Variants during Large Nationwide Outbreak of COVID-19, Vietnam, 2021
Tam NT., Anh NT., Tung TS., Thach PN., Dung NT., Trang VD., Hung LM., Dien TC., Ngoc NM., Duyet LV., Cuong PM., Phuong HVM., Thai PQ., Tung NLN., Man DNH., Phong NT., Quang VM., Thoa PTN., Truong NT., Thao TNP., Linh DP., Tai NT., Bao HT., Vuong VT., Nhung HTK., Hong PND., Hanh LTP., Chung LT., Nhan NTT., Thanh TT., Hung DT., Mai HK., Long TH., Trang NT., Thuong NTH., Hong NTT., Nhu LNT., Ny NTH., Thuy CT., Thanh LK., Nguyet LA., Mai LTQ., Thuong TC., Nga LH., Thanh TT., Thwaites G., van Doorn HR., Chau NVV., Kesteman T., Tan LV., Chambers M., Choisy M., Trinh DHK., Tam DTH., Duc DH., Viet DVT., Fisher J., Flower B., Geskus R., Kim HVT., Chanh HQ., Hai HTB., Hien HV., Bao HV., Thao HD., Huy HLA., Ha HN., Trieu HT., Yen HX., Kestelyn E., Lawson K., Jones L., Khoa LDV., Nhat LTH., Lewycka SO., Yen LM., Lan LTH., Nguyen NV., Hoa NT., Tran NB., Manh ND., Yen NH., My NLT., Nguyet NM., Ha NT., Quyen NTH., Ngoc NT., Nhien NTT., Yen NTH., Trang NTH., Ngoc NTK., Tuyen NTK., Diep NTN., Dung NTP., Thuong NTT., Truong NX., Phuong ND., Van NTT., Thinh OP., Thanh PN.
We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions.