Long-term Memory Response After a Single Intramuscular Rabies Booster Vaccination 10-24 Years After Primary Immunization

Background Published data regarding long-lasting immunological rabies memory after pre-exposure prophylaxis (PrEP) are scarce. We tested the hypothesis that rabies booster immunization elicits rapid anamnestic responses. Methods For this observational study, we included participants who had received PrEP 10-24 years before inclusion. We measured rabies antibody titers before, and on days 3, 7, and 14 after a single intramuscular booster. Results All 28 participants responded adequately regardless of route of administration or 2-dose vs 3-dose PrEP regimen. Conclusion Rabies immunological memory is reactivated within 7 days after a single intramuscular booster immunization, even when administered 10-24 years after PrEP.