Abstract
Age distribution of antibody to herpes simplex virus (HSV) in Fukuoka, Manila and Busan was investigated by the neutralization test. The results show that a large number of young people lack antibody to HSV in Fukuoka, but not in Manila or Busan. In Manila and Busan, the rates of positive neutralizing antibody to HSV in younger generations are maintained at high levels, showing a significant difference from that of Fukuoka. Such difference is considered to have been derive from the differet socioeconomical standards and sanitary conditions.