Factors influencing the immune response after a single-dose 3-visit pre-exposure rabies intradermal vaccination schedule: A retrospective multivariate analysis

• Published in: Travel medicine and infectious disease Vol. 37; p. 101867
• Main Authors: Damanet, Benjamin, Costescu Strachinaru, Diana Isabela, Van Nieuwenhove, Mathias, Soentjens, Patrick
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.09.2020; Elsevier Limited
• Subjects: Age; Antibodies; Antiretroviral drugs; Armed forces; Defence mechanisms; Disease control; Disease prevention; Disease prophylaxis; Gender; Immune response; Immunity; Infectious Disease; Infectious diseases; Military personnel; Multivariate analysis; Neglected preventable disease; Prophylaxis; Rabies; Schedules; Serology; Tetanus; Travel medicine; Tropical diseases; Vaccination; Vaccination schedule; Vaccines; Whooping cough; Belgium; Neglected preventable disease; Vaccines; Rabies; Vaccination schedule
• ISSN: 1477-8939; 1873-0442; 1873-0442
• DOI: 10.1016/j.tmaid.2020.101867

The World Health Organization (WHO) recommends intradermal (ID) rabies vaccination as a safe and immunogenic alternative to intramuscular administration. The aim of this study is to determine which factors influence the levels of rabies virus neutralizing antibodies (RVNA) after a 3-visit ID rabies vaccination. This is a retrospective secondary data analysis study based on electronic health record vaccination data of Belgian military subjects who received ID rabies Pre-exposure prophylaxis (PrEP) with a single-dose 3-visit regimen during the period 2014–2017. Logistic regression was performed to identify predictive factors of RVNA level ≥3.0 IU/mL and >10 IU/mL. The second analysis performed on the 2025 subjects (100% seroconverted with a RVNA ≥ 0.5 IU/mL) shows a significantly better immune response in subjects younger than 30 years compared to all other age-groups, a gender-difference to predict RVNA ≥ 3.0 IU/mL (OR 2.30 [1.26–4.22] comparing “female” to “male”) and the influence of the vaccination schedule (OR 2.28 [1.15–4.53] comparing “late - very variable” to “correct” schedule) to predict > 10 IU/ml. Multivariate analysis also demonstrates that a postponed serology control significantly influences the Rapid Fluorescent Focus Inhibition Test (RFFIT). Gender and age significantly influence the response to ID rabies vaccine. Timing of RVNA determination is important to correctly assess the response to vaccination. A single-dose 3-visit ID rabies PrEP schedule is a dose-sparing effective alternative to the double-dose 2-visit ID schedule. When the minimum time interval between doses is respected, RVNA determination is not necessary. •Gender and age significantly influence the response to single-dose 3-visit ID rabies PrEP schedules.•Single-dose 3-visit ID rabies PrEP schedules are an effective dose-sparing alternative in case of vaccine shortages.•When the minimum time interval between doses is respected, RVNA determination is not necessary.•Timing of RVNA determination is important to correctly assess the response to vaccination.