Vu, Trang Thu, Tu Huy Ngo, Khanh Cong Nguyen, Vu Thi Lan, Cu Thi Bich Hanh, Le Hong Son, Huyen Thi Nguyen, et al. “Within-Household SARS-CoV-2 Transmission and Vaccine Effectiveness in the First Three COVID-19 School Outbreaks in Northern Viet Nam, September–December 2021”. Western Pacific Surveillance and Response 15, no. 3 (July 11, 2024). Accessed May 30, 2026. https://ojs.wpro.who.int/ojs/index.php/wpsar/article/view/1077.