Washington University WU 409: Immune Responses to Rabies Vaccine.

WU 409: Immune Responses to Rabies Vaccine in the Presence and Absence of Neutralizing Antibodies

This study will evaluate the immune response to rabies vaccination persons 18 years and older. We will evaluate thirty healthy participants across three cohorts: 1) standard rabies pre-exposure prophylaxis regimen (two doses of Imovax® or RabAvert® seven days apart with no RIG); 2) rabies pre-exposure prophylaxis regimen + day 0 RIG (two doses of Imovax® or RabAvert® seven days apart, with RIG administered at day 0); 3) rabies pre-exposure prophylaxis regimen + day 28 RIG (two doses of Imovax® or RabAvert® seven days apart, with RIG administered at day 28).

Study Overview

• Status: Completed
• Conditions: Healthy Participants
• Intervention / Treatment: Drug: Imovax; Drug: RabAvert; Drug: HyperRAB

Detailed Description

This study will evaluate the immune response to rabies vaccination persons 18 years and older. We will evaluate thirty healthy participants across three cohorts: 1) standard rabies pre-exposure prophylaxis regimen (two doses of Imovax® or RabAvert® seven days apart with no RIG); 2) rabies pre-exposure prophylaxis regimen + day 0 RIG (two doses of Imovax® or RabAvert® seven days apart, with RIG administered at day 0); 3) rabies pre-exposure prophylaxis regimen + day 28 RIG (two doses of Imovax® or RabAvert® seven days apart, with RIG administered at day 28).

RANDOMIZATION PROCEDURES Participants will be randomized 1:1 to either:

Arm-1 Imovax or RabAvert- 2 doses 7 days apart or Arm-2 Imovax or RabAvert- 2 doses 7 days apart with RIG at day 0

Once 20 participants are enrolled to arms 1 and 2 10 more participants will be enrolled to:

Arm-3 Imovax or RabAvert- 2 doses 7 days apart with RIG at day 28

We plan to enroll 30 evaluable participants in the coming year, anticipating up to 30 enrolling in the optional FNA and BMA assessments

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Early Phase 1

Contacts and Locations

Study Locations

• United States
  • Missouri
    • St Louis, Missouri, United States, 63110
      • Washington University School of Medicine Infectious Disease Clinical Trials Unit.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

- 1. Healthy participants over 18 years of age. 2. Able to understand and give informed consent. 3. Willing to receive rabies vaccine 4. In stable health, as determined by medical history and targeted physical exam related to this history.

5. For those willing to give FNA, CBL and BMA samples, Willing to: give FNA specimens OR give CBL specimens OR give bone marrow aspirates OR give both FNA and BMA specimens OR give both FNA and CBL specimens OR give FNA, CBL and BMA specimens

Exclusion Criteria:

1. Receipt of prior rabies vaccination or risk for rabies exposure requiring standard vaccination
2. Has a current or previous diagnosis of immunocompromising condition to include human immunodeficiency virus, immune-mediated disease requiring immunosuppressive treatment, or other immunosuppressive condition.
3. Has received systemic immunosuppressants or immune-modifying drugs for > 14 days in total within 6 months prior to Screening (for corticosteroids ≥ 10 mg/day of prednisone equivalent) or is anticipating the need for immunosuppressive treatment at any time during participation in the study.
4. Is acutely ill or febrile (temperature >38.0 C [100.4F] less than 72 hours prior to or at the day 1 visit. Participants who meet this criteria may be rescheduled.
5. Currently has symptomatic acute or unstable chronic disease requiring medical or surgical care, to include significant change in therapy or hospitalization, at the discretion of the investigator.
6. History of excessive alcohol consumption, drug abuse, psychiatric conditions, social conditions or occupational conditions that in the opinion of the investigator would preclude compliance with the study.
7. Has received any vaccine ≤ 28 days prior to the injection (Day 1) or plans to receive a vaccine within 28 days before or after the study injection. These participants may be rescheduled.
8. Pregnant women and nursing mothers or women who are planning to become pregnant for the study duration.
9. Have donated blood, blood products or bone marrow within 30 days before study vaccination, plan to donate blood at any time during the duration of participant study participation, or plan to donate blood within 30 days after the last blood draw.
10. Any condition in the opinion of the investigator that would interfere with the proper conduct of the trial.
11. Coagulopathy (primary or iatrogenic) which would contraindicate bone marrow aspirate or core lymph node biopsy for participants willing to have those procedures done

12. Known IgA deficiency, as this is a known risk factor for anaphylactic reactions to Rabies immunoglobulin.

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Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Arm-1 Imovax or RabAvert- 2 doses 7 days apart; Imovax or RabAvert- 2 doses 7 days apart	Drug: Imovax; Rabies Vaccine; Drug: RabAvert; Rabies Vaccine; Other Names: RabAver
Experimental: Arm 2 Imovax or RabAvert- 2 doses 7 days apart with RIG at day 0; Imovax or RabAvert- 2 doses 7 days apart with RIG at day 0	Drug: Imovax; Rabies Vaccine; Drug: RabAvert; Rabies Vaccine; Other Names: RabAver; Drug: HyperRAB; rabies immune globulin (human)
Experimental: Arm 3 Imovax or RabAvert- 2 doses 7 days apart with RIG at day 28; Imovax or RabAvert- 2 doses 7 days apart with RIG at day 28	Drug: Imovax; Rabies Vaccine; Drug: RabAvert; Rabies Vaccine; Other Names: RabAver; Drug: HyperRAB; rabies immune globulin (human)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Comparison of antibody titers at D28 versus baseline	Comparison of antibody titers at D28 versus baseline	28 days
Comparison of antibody titers at D365 versus baseline	Comparison of antibody titers at D365 versus baseline	365 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Frequency serious adverse events	Number of serious adverse events reported	time of consent to day 365

Collaborators and Investigators

• Sponsor: Washington University School of Medicine
• Investigators: Principal Investigator: Rachel Presti, MD PhD, Washington University School of Medicine

Study record dates

Study Major Dates

• Study Start (Actual): July 18, 2023
• Primary Completion (Actual): May 27, 2025
• Study Completion (Actual): October 1, 2025

Study Registration Dates

• First Submitted: January 27, 2026
• First Submitted That Met QC Criteria: February 3, 2026
• First Posted (Actual): February 10, 2026

Study Record Updates

• Last Update Posted (Actual): February 10, 2026
• Last Update Submitted That Met QC Criteria: February 3, 2026
• Last Verified: July 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Biological Products; Complex Mixtures; Vaccines; Viral Vaccines; Rabies Vaccines
• Other Study ID Numbers: 202305094; PJ000006488 (Other Grant/Funding Number: Institutional Grant/Award Human Clinical Studies fund)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Sharing Time Frame: ICF is attached Protocol is attached CSR within 30 days of completion.
• IPD Sharing Access Criteria: ICF is attached Protocol is attached
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No