The protective effect of the large-scale use of PHKC rabies vaccine in humans in China.

Reported are the results obtained with different immunization schedules of adjuvant or freeze-dried concentrated (FDC) primary hamster kidney cell (PHKC) rabies vaccine on volunteers. The FDC vaccine (potency, 4.5 IU), which was inoculated in six doses, on days 0, 3, 7, 14, 30 and 90, and the adjuvant vaccine (potency 2.5 IU), which was inoculated in five doses, on days 0 and 7 (double dose), 14, 30 and 90, induced earlier, higher, and more persistent neutralizing antibody titres than the adjuvant vaccine which was inoculated in five doses on days 0, 3, 7, 14 and 30. The persistence of the neutralizing antibody titres induced by three intradermal doses of vaccine administered on days 0 (4 sites), 7 (2 sites), and 28 (1 site) was lower than that induced by six intramuscular doses administered on days 0, 3, 7, 14, 30, and 90. A cell-mediated immunity (CMI) was also induced in vaccinees who received the adjuvant vaccine. The protective effect of the adjuvant vaccine was better than that of the previously used Semple vaccine and has had a positive effect on the epidemiology of human rabies in China.