Long-Term Humoral Immune Response in Persons with Asymptomatic or Mild SARS-CoV-2 Infection, Vietnam oleh Huynh Kim Mai, Nguyen Bao Trieu, Trinh Hoang Long, Hoang Tien Thanh, Nguyen Dinh Luong, Le Xuan Huy, Lam Anh Nguyet, Dinh Nguyen Huy Man, Danielle E. Anderson, Tran Tan Thanh, Nguyen Van Vinh Chau, Guy Thwaites, Lin-Fa Wang, Le Van Tan, Do Thai Hung