CompletedNot Applicable

Immunogenicity Assessment of Subjects Receiving Rabies Post-exposure Prophylaxis in Cambodia

Cambodia215 participantsStarted 2020-07-15

Plain-language summary

A rabies virus neutralizing antibody (RVNA) concentration ≥ 0.5 IU/ml at 14 days after immunization is considered a proxy for protection in vaccine efficacy studies. Abridged and dose-sparing vaccination regimens increase accessibility and reduce both direct and indirect costs, especially in resource-constrained countries where RABV prevalence is highest. Several efficacy studies evaluated safety and immunogenicity of abridged regimens in healthy adult volunteers using either four-site intradermal (ID) or intramuscular (IM) regimens, showing them to be safe and immunogenic. Researchers at the Institut Pasteur du Cambodge (IPC) have previously conducted a retrospective study on clinical outcome at ≥6 months in 3318 Cambodians who received intradermal Vero cell vaccine post-exposure prophylaxis after a bite by a rabid or sick-looking but untested dog in 2003-2014. Here, the investigators could show that there was no significant difference in survival among patients who received 3 versus 4 sessions of the Thai Red Cross (TRC) ID regimen. In a separate study, investigators measured antibody responses in order to evaluate the immunogenicity of the TRC regiment after 3 sessions versus 4 sessions. The investigators did not observe an increase in rabies virus seroneutralization titers 14 days after the fourth immunization compared to 14 days after the third immunization. These results contributed to changes endorsed by the WHO in its April 2018 guidelines. The "Institut Pasteur du Cambodge (IPC) regimen" of three PEP sessions of two-site ID 0.1 mL vaccine doses each at days 0, 3 and 7 is the first one-week PEP regimen to be recommended. In the current research project, the aim is to compare further different PEP vaccination strategies in a real life setting of individuals attending the rabies vaccination center at Institut Pasteur du Cambodge (IPC) in Phom Penh, Cambodia. The antibody kinetics and cellular immune responses in patients following either the one-week, 2-site ID regimen (IPC regimen) or the two-week IM regimen (4-dose regimen) as well as the participants' survival for both protocols after 6 months are evaluated.

Who can participate

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Subjects entering a rabies post-exposure vaccination course whatever the vaccine used with or without administration of rabies immunoglobulin (RIGs). * Subjects with ability to attend all scheduled visits and to comply with all study procedures Exclusion Criteria: * Subjects with history of previous rabies vaccination

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Changes of the level of rabies virus neutralizing antibodies at 14 days and 18 days after first dose among patients receiving post-exposure prophylaxis (PEP) using intramuscular (IM) and intradermal (ID) protocols

Timeframe: Day 0 (the first PEP dose), then 14 days and 28 days after Day 0 in each study group (IM / ID)

Trial details

NCT IDNCT05684185

SponsorInstitut Pasteur du Cambodge

Sponsor typeOTHER

Study typeOBSERVATIONAL

Primary completion2022-04-01

View on ClinicalTrials.gov More Rabies Post-exposure Prophylaxis trials