[1] Ramathibodi Hosp, Res Ctr, Fac Med, Bangkok 10400, Thailand
[2] Ramathibodi Hosp, Dept Pediat, Fac Med, Bangkok 10400, Thailand
[3] Ramathibodi Hosp, Dept Pathol, Fac Med, Bangkok 10400, Thailand
[4] Ramathibodi Hosp, Dept Nursing, Fac Med, Bangkok 10400, Thailand
[5] Mahidol Univ, Ctr Vaccine Dev, Inst Sci & Technol Res & Dev, Nakhon Pathom 73000, Thailand