[1] Hiroshima Univ, Grad Sch Biomed & Hlth Sci, Dept Epidemiol Infect Dis Control & Prevent, Minami Ku, 1-2-3 Kasumi, Hiroshima 7348551, Japan
[2] Minist Hlth Cambodia, Payment Certificat Agcy, Phnom Penh, Cambodia
[3] Unite Rech Clin Nanoro URCN, Nanoro, Burkina Faso
[4] Univ Puthisastra, Fac Med, Phnom Penh, Cambodia
[5] WHO, Country Off, Expanded Programme Immunizat, Phnom Penh, Cambodia
[6] Minist Hlth, Natl Immunizat Programme, Phnom Penh, Cambodia
[7] Univ Hlth Sci, Phnom Penh, Cambodia