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.