Systematic sequencing of imported cases leads to detection of SARS-CoV-2 B.1.1.529 (Omicron) variant in central Viet Nam

• Published in: Western Pacific surveillance and response journal Vol. 13; no. 4; pp. 1 - 95
• Main Authors: Hung, Do Thai, Trieu, Nguyen Bao, Thuy, Do Thi Thu, Olmsted, Allison, Long, Trinh Hoang, Duy, Nguyen Duc, Mai, Huynh Kim, Hien, Bui Thi Thu, Van Van, Nguyen, Van Kiem, Tran, Trang, Vo Thi Thuy, Duy, Nguyen Truong, Thanh, Ton That, Van Dong, Huynh, Gould, Philip, Moore, Matthew
• Format: Journal Article
• Language: English
• Published: Philippines World Health Organization 01.10.2022
• Subjects: COVID-19; Health Personnel; Humans; SARS-CoV-2; Vietnam; Vietnam
• ISSN: 2094-7321; 2094-7313
• DOI: 10.5365/wpsar.2022.13.4.977

As authorities braced for the arrival of the Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), infrastructure investments and government directives prompted action in central Viet Nam to establish capacity for genomic surveillance sequencing. From 17 November 2021 to 7 January 2022, the Pasteur Institute in Nha Trang sequenced 162 specimens from 98 150 confirmed SARS-CoV-2 cases in the region collected from 8 November to 31 December 2021. Of these, all 127 domestic cases were identified as the B.1.617.2 (Delta) variant, whereas 92% (32/35) of imported cases were identified as the B.1.1.529 (Omicron) variant, all among international flight passengers. Patients were successfully isolated, enabling health-care workers to prepare for additional cases. Most (78%) of the 32 Omicron cases were fully vaccinated, suggesting continued importance of public health and social measures to control the spread of new variants.