Ung, Trang thi Hong, Phuong Vu Mai Hoang, Son Vu Nguyen, Hang Le Khanh Nguyen, Phuong thi Kim Nguyen, Dan Tan Phan, Thanh Thi Le, Anh Phuong Nguyen, Thach Co Nguyen, Futoshi Hasebe, and Mai thi Quynh Le. 2022. “Occurrence of the Omicron Variant of SARS-CoV-2 in Northern Viet Nam in Early 2022: Omicron Variant in Northern Viet Nam, Early 2022”. Western Pacific Surveillance and Response 13 (3):5. https://doi.org/10.5365/wpsar.2022.13.3.955.