IgM and IgG antibody profiles after immunization of man with a HDCS-vaccine (preliminary communication)

HDCS vaccine was given to 20 healthy, not rabies-exposed people on days 0, 3, 7, 14, 28 and 90. Ten of them received in addition 20 IU/kg of human antirabies immunoglobulin. Vaccine potency in NIH tests was 1.8 (WHO). Most individuals did not show any measurable neutralizing antibody titer on days 3 and 7. On days 14, 28, 90 and 300 the mean of titres was above 1:200; with one exception, no titer was lower than 1:50. The sera of days 14 and 90 were separated on "Sephadex G-200" columns. On day 14 at least 46% of the rabies antibody was found in the IgM fraction, while 15% was recovered from the IgG fraction. On day 90 the proportion recovered from the IgM fraction had decreased to 17%; the IgG antibody had increased to 30% of the titres found in whole serum. Almost no antirabies activity was found in the IgG fractions.