Rabies vaccine prepared in human diploid cell strains is a replacement for the previously available vaccines that are prepared in animal tissues and are less immunogenic and more reactogenic. The human cel-grown vaccine made in the United States is a split-product vaccine, whereas the vaccines made in Europe are whole-virion vaccines. Both types of vaccine contain concentrated and inactivated "fixed" rabies virus. When used before exposure to rabies virus, the vaccine should be given intramuscularly in three 1-ml doses on days 0, 7, and 21. Immediately after exposure to rabies virus, a person should be given human rabies immune globulin (20 international units/kg). This treatment should be followed by five intramuscular doses of vaccine given on days 0, 3, 7, 14, and 28. For maintenance of long-term immunity in persons continously exposed to the risk of rabies, booster doses of the vaccine should be given at two-year intervals.