Detection of co-infection and recombination cases with Omicron and local Delta variants of SARS-CoV-2 in Vietnam.
Trang NT., Dien TC., Tam NT., Cuong PM., Van Duyet L., Thuong NTH., Trang VD., Thach PN., van Doorn HR., Kesteman T., OUCRU COVID-19 research group None.
The first nationwide outbreak of COVID-19 in Vietnam started in late April 2021 and was caused almost exclusively by a single Delta lineage, AY.57. In early 2022, multiple Omicron variants co-circulated with Delta variants and quickly became dominant. The co-circulation of Delta and Omicron happened leading to possibility of co-infection and recombination events which can be revealed by viral genomic data. From January to October 2022, a total of 1028 viral RNA samples out of 4852 positive samples (Ct