SARS-COV-2 VARIANT CIRCULATION IN BRUNEI DARUSSALAM - NOVEMBER 2021 TO JULY 2022.
Mirza AZMI1, Zainun ZAINI1, Haziq MOMIN2, Nor Azian HAFNEH2, Nur Amirah IBRAHIM2, Izzati AZHAR2, Nabihah AHMAD2, Husnina KHAIRIL2.
1National Virology Reference Laboratory, Department of Laboratory Services, Ministry of Health, Brunei Darussalam.
2Microbial Genomic Services, Department of Laboratory Services, Ministry of Health, Brunei Darussalam.
ABSTRACT
This is a report of 8-months progression of circulating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants in Brunei Darussalam from November 2021. Whole-genome sequencing (WGS) was performed on nearly 3,000 random local COVID-19 patients in samples with a cycle-threshold (CT) of less than 25. Phylogenetic analysis revealed that the Delta variant, particularly AY.24.1, was the predominant variant towards the end of 2021. The same variant was then completely superseded by the Omicron variants in mid-January 2022. During the early wave of Omicron variants, BA.2.3.19 and its paternal BA.2.3 were found to be the prominent sublineage until it was replaced by BA.5 lineages four months later, mainly BA.5.2 and BF.5. Further analysis revealed that AY.24.1 and BA.2.3.19 that was once a prevalent variant are predominantly observed in Brunei. Both variants can be differentiated by the presence of a particular mutation in the S gene that encodes the viral spike protein that is essential for host cell interaction. Brunei is continuously monitoring the circulating SARS-CoV-2 variants as part of its genomic surveillance following the World Health Organization (WHO) guidance for surveillance.
Keywords: Brunei, Next-generation sequencing, SARS-CoV-2, SARS-CoV-2 variants, Whole-genome sequencing.
Corresponding author: Zainun binti Zaini, National Virology Reference Laboratory, Department of Laboratory Services, Ministry of Health, Brunei Darussalam.
+673 2221821 ext. 107/114
Email: zainun.zaini@moh.gov.bn
Brunei Int Med J.2023;19:79-84