Boostability Assessment of Three Rabies Pre-Exposure Regimens in Healthy Volunteers 5 Years Following Priming.
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Booster vaccination.
- Who it may be relevant to
- Registry conditions: Rabies (Healthy Volunteers). Basic parameters: 18 years — 60 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Belgium
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Official title
A Multicentre, Open-label Trial in Healthy Volunteers to Assess the Boostability of Three Different Rabies Pre-exposure Prophylaxis Regimens When Administering a Single-dose, Intramuscular Vaccination as Simulated Post-exposure Prophylaxis at Least Five Years Following Priming.
Overview
A multicentre, open label trial in healthy volunteers to assess the boostability of three different rabies pre-exposure prophylaxis regimens (2 x 1IM regimen, 2 x 2 ID regimen, 1 x 2 ID regimen) when administering a single-dose, intramuscular vaccination as simulated post-exposure prophylaxis at least five years following priming.
Detailed description
This multicentre clinical trial will include 561 participants, allocated evenly across 3 groups (187 per group). Participants are assigned to one of three groups according to their prior PrEP regimen, provided their last dose was given at least 5 years prior to enrollment.
• Group 1: 21IM regimen, (N = 187): received PrEP at least 5 years ago through 1 x 1,0 mL IM injection (Day 0 and Day 7), with a 7-day interval between visits (interval of 5 to 56 days is allowed).
• Group 2: 2²ID regimen (N = 187): received PrEP at least 5 years ago through 2 x 0,1 mL ID injections (Day 0 and Day 7) with a 7-day interval between visits (interval of 5 to 56 days is allowed).
• Group 3: 1²ID regimen (N = 187): received PrEP at least 5 years ago through 2 x 0,1 mL ID injections on Day 0
All subjects will receive 1 x 1,0 mL IM injection of purified chick-embryo cell-culture rabies vaccine as sPEP (booster) at least five years after primary vaccination (PrEP).
Neutralizing antibody titers against rabies virus will be measured using the Rapid Fluorescent Focus Inhibition Test (RFFIT) on Day 0 (before administration of sPEP) and on Days 7 and 14 after sPEP vaccination.
A titre of ≥ 0.5 IU/mL is defined as adequate (WHO standard).
Interventions
- Biological Booster vaccination
To investigate whether the boostability of a (A) two-visit IM, (B) two-visit ID and (C) one-visit ID pre-exposure vaccination regimen is non-inferior to a theoretical 99% boostability by administering a single-dose IM booster to simulate exposure to rabies at least 5 years after the pre-exposure regimens regimen.
Primary outcome measures
- Primary: boostability [Time frame: 13 months - from First Patient In (FPI) to Last Patient Out (LPO)]
Secondary outcome measures (7)
- RFFIT levels ≥ 0.5 IU/mL Day 14 [Time frame: 14 days following booster vaccination]
- FFIT levels ≥ 0.5 IU/mL on the day of the booster (Day 0). [Time frame: Day 0 - on day of booster vaccination]
- RFFIT levels ≥ 3.0 IU/mL on Day 7 after the booster [Time frame: Day 7 - following booster vaccination]
- RFFIT levels ≥ 3.0 IU/mL on Day 14 after the booster. [Time frame: Day 14 after the booster vaccination]
- RFFIT levels ≥ 10 IU/mL on Day 7 after the booster. [Time frame: Day 14 following the booster vaccination]
- RFFIT levels ≥ 10 IU/mL on Day 14 after the booster. [Time frame: Day 14 following the booster vaccination.]
- Safety objectives [Time frame: 1. & 2. Day 7 following the booster vaccination. 3. 13 months - entire study duration FPI to LPO]
Eligibility criteria
Inclusion criteria
- ≥ 18 to ≤ 60 years of age at time of inclusion
- Willingness to provide written informed consent
- Having received PrEP with a 21IM, 2²ID or 1²ID regimen at least 5 years before starting the study. For 21IM and 2²ID interval of 5 days to 56 days between the 2 visits is allowed.
Exclusion criteria
- Known allergy to one of the components of the vaccine.
- Subjects, who received immunomodulating therapy within the last 3 months (12 weeks).
Note: See Section 6.3 for detailed guidance on immunomodulating therapies.
- Planned vaccination with any inactivated vaccine within 2 weeks before or after vaccination in the study or with any live attenuated vaccine within 1 month before or after each vaccination in the study.
- Ongoing pregnancy or active child wish at the time of booster vaccination (D0).
- Any other PrEP rabies vaccine schedule/vaccination than mentioned in the inclusion criteria.
- Previous rabies (s)PEP
- Inability or unwillingness to comply with study procedures, including protocol-defined visits, assessments, or interventions.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Non-randomized
- Model
- Parallel assignment
- Masking
- Open label
- Primary purpose
- Prevention
Study locations
Belgium · 6 centers
- Clinical Trial Site Insitute of Tropical Medicine — Antwerp
- Cliniques Universitaires de Saint Luc — Brussels
- Centrum voor vaccinologie (CEVAC) — Ghent
- UZ Brussel — Jette
- Centre Hospitalier Universitaire de Liège — Liège
- Military Hospital Queen Astrid — Neder-Over-Heembeek
Identifiers
NCT: NCT07455318 · BAZOOKA_221 · 2025-524765-24-00