WHO Recommended Pre-exposure Prophylaxis for Rabies Using Japanese Rabies Vaccine

After severe exposure to suspected rabid animal, WHO recommends a complete vaccine series using a potent effective vaccine that meets WHO criteria, and administration of rabies immunoglobulin (RIG). RIG is not available globally, and is not marketed in Japan. If pre-exposure prophylaxis for rabies is given, RIG is unnecessary even after severe exposure. It is thus important to give pre-exposure prophylaxis for rabies to people who plan to go to rabies-endemic areas. In Japan, pre-exposure prophylaxis for rabies consists of 3 doses of cell-culture rabies vaccine. The first two doses are given 4 weeks apart, and the third dose is given 6-12 months after the first dose, all of which are injected subcutaneously (standard regimen). People who plan to travel abroad to rabies-endemic areas may know of their destinations only 1 or 2 months in advance at best. Therefore, it is virtually impossible to complete the 3 dose regimen for rabies in Japan. Pre-exposure prophylaxis recommended by WHO consists of 3 doses given intramuscularly on days 0, 7, and 28, making it possible to complete pre-exposure prophylaxis in one month. This WHO recommended pre-exposure prophylaxis using Japanese cell-cultured rabies vaccine (PCEC-K) has not been studied, so we elected to fill the gap using PCEC-K, administered based on the WHO recommendation and examined its efficacy and safety. Subjects were 26 healthy volunteers with no previous rabies vaccination giving oral and written consent. Vaccine was administered on days 0, 7, and 28, and rabies antibody levels were tested on days 7, 28, and 42. On day 7, every antibody level was negative. On day 28, antibody levels were between 0.7-3.5 EU/ mL, with the exception of 3 cases still negative. On day 42, all cases, including the 3 negative cases, exceeded 1.6 EU/mL, providing sufficient protection against rabies. This result was not inferior compared to the standard regimen. Local adverse effects such as erythema and pain were noted, but none were serious. In conclusion, WHO recommended pre-exposure prophylaxis for rabies using PCEC-K is considered effective and safe.