T and B cell human responses to European bat lyssavirus after post‐exposure rabies vaccination

T and B cell human responses lo European bat lyssavirus (EBL1) induced by post‐exposure rabies vaccination (PM virus vaccine) were evaluated by measuring plasmatic titres of EBL1‐specific neutralizing antibodies; specific EBL1‐binding antibodies; and proliferation indices of peripheral blood lymphocytes stimulated in vitro with EBL1. These parameters for vaccination efficacy were compared with those obtained with vaccine‐related viruses (CVS and ERA) and with a non‐vaccine‐related virus, Mokola virus, the last implicated in vaccination failures. Twenty‐two patients exposed to rabies risk who received a reduced rabies post‐exposure vaccination were involved in the study. On day 21, vaccine induced CVS‐specific neutralizing antibodies in all patients; but EBL1‐spccific neutralizing antibodies were induced in only 73% of patients. No vaccinee had Mokola‐specific neutralizing antibodies. Patients having EBL1‐specific neutralizing antibodies were usually those in whom vaccination induced high titres of CVS‐specific neutralizing antibodies. On day 21, peripheral blood lymphocytes of 86% of patients could be restimulaled in vitro with vaccine, 43% with EBL1 and 45% with Mokola. Patients exhibiting a high vaccine‐specific proliferation response more likely developed an EBL1‐or a Mokola‐specific proliferalive response. No correlation was found between T and B cell responses. Rabies vaccination induced neither T nor B cell EBL1‐specific responses in 22% of patients.