[1] Int Vaccine Inst, Epidemiol Unit, Seoul, South Korea
[2] Univ Oxford, Clin Res Unit, Wellcome Trust Major Overseas Programme, Hosp Trop Dis, Ho Chi Minh City, Vietnam
[3] Univ Cambridge, Dept Med, Cambridge, England
[4] Eberhard Karls Univ Tubingen, Inst Trop Med, Tubingen, Germany
[5] Duy Tan Univ, Da Nang, Vietnam