1. Ho Chi Minh City University of Medicine and Pharmacy, Ho Chi Minh City, Viet Nam.
2. Department of Clinical Product Development, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan.
3. Hue University of Medicine and Pharmacy, Hue City, Viet Nam.
4. Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN), Nagasaki, Japan.