Collaborative study: Standardization of Japanese reference diphtheria and tetanus toxoids, (adsorbed, lot 2), for potency determination of diphtheria-tetanus- acellular pertussis combined vaccine.
Department of Bacterial Pathogenesis and Infection Control, National Institute of Infectious Diseases, Musashimurayama, Tokyo 208-0011, Japan. miwaki@nih.go.jp