Intradermal rabies vaccination: the evolution and future of pre- and post-exposure prophylaxis.

Inactivated rabies vaccines have been used to pioneer the immunological and economical advantages of intradermal (ID) administration over 35 years. Vaccine shortages or its prohibitive cost stimulated studies of various doses, frequency and sites of injection. An economical regimen for pre-exposure prophylaxis requires one-tenth of an intramuscular dose, but the early popularity of the method has been stifled by pharmaceutical regulations. There has also been reluctance to use multiple-site post-exposure ID regimens, except in a very few Asian counties. A new four-site ID regimen could overcome many of the problems encountered to date. The time is ripe to make dramatic progress towards efficient use of the current excellent vaccines globally, wherever there is a shortage of vaccine or funds.