Intradermal immunization with rabies vaccine. Inactivated Wistar strain cultivated in human diploid cells.

We report a comparative study of the Mérieux Institute's inactivated rabies vaccine administered intradermally or subcutaneously. Vaccine safety was satisfactory, with only minor local and generalized reactions. Serological effectiveness was outstanding: all of those who had been seronegative became seropositive following either two intradermal or subcutaneous injections given one month apart. A comparison of the intradermal and subcutaneous routes demonstrated several important points. Antibody titers developing after subcutaneous immunization were greater than after intradermal immunization. The kinetics of antibody development during primary immunization were parallel in the two immunization protocols. Eleven months after primary immunization, subcutaneous administration of a booster dose of vaccine resulted in a titer elevation 1.86-fold greater than that in intradermal administration. Each of these levels indicated good serological response.