Humoral response (virus-neutralizing antibody production) to immunization with inactivated 30-fold concentrated and purified tissue culture rabies vaccine was studied in monkeys and human volunteers. Two doses of the preparation spaced 20 days apart and given intramuscularly or intradermally to monkeys induced in them much more intensive antibody production (4--213-fold by titer) than 6 daily injections of unconcentrated vaccine. In 10 human volunteers immunized with 1.5 ml doses of the concentrated vaccine intramuscularly twice 20 days apart antibody titers 40 days after immunization varied from 1:79 to 1:6250 (average 1:1067). In another group of 10 human volunteers immunized intramuscularly with the concentrated vaccine 3 times at 0, 1st and 20th day, antibody titers 40 days after immunization were 1:112--1:3273 (average 1:508). These values are significantly higher than the average titers in humans vaccinated with unconcentrated tissue culture of brain vaccine of Fermi type. The concentrated vaccine proved to be a preparation of low reactogenicity: no systemic reactions were observed among vaccinated volunteers; 4 out of 20 volunteers had a mild, transient (1 day) local reaction (hyperemia of less than 1.5 cm in diameter).