[The early death phenomenon related to sensitization of mice with rabies antigen--qualitative study and kinetics]

Protection against challenge following rabies vaccination occurs early in the mouse. However, before this protection appears, vaccinated mice die earlier than control mice receiving a placebo. Study of this 'early death' shows that this phenomenon occurs when challenge is made with the CVS fixed virus and a field isolate from the salivary glands of the fox; by different routes of inoculation and for various infectious doses, and finally, when this challenge is made before or after vaccination. This phenomenon can be transferred via spleen cells or plasma of vaccinated animals into infected recipients. Lack of thymus in the mouse prevents early death, but reduction of B lymphocytes population by cyclophosphamide have no effect on this death. Kinetic studies of different parameters, taken into account when studying this phenomenon, show fluctuations of the survival time after challenge in inoculated mice, as well as in controls. As a consequence of these fluctuations, a shift between mortalities of vaccinated animals and controls is observed.