An observational study in Oropouche Infection, sponsored by Institut Pasteur. Not yet recruiting. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-06.
Sponsored by Institut Pasteur · Observational
Oropouche virus (OROV), a re-emerging South American arbovirus causing dengue-like fever and occasional neurological complications, is expanding its circulation towards more densely populated areas in French Guiana, as evidenced by recent cases near Cayenne in 2026. While animal models indicate that B cell-mediated humoral immunity is critical for viral control, the human antibody response to OROV remains poorly characterized. Despite WHO-led international research efforts, there is currently no vaccine, antiviral treatment, or described human monoclonal antibody against OROV - a major gap that hinders therapeutic and vaccine development. Identifying human neutralizing monoclonal antibodies could offer a promising therapeutic option, particularly for vulnerable populations such as pregnant women.
The goal of this project is to characterize the adaptive immune response to OROV infection during the convalescent phase.
The study is based on three complementary populations: (1) 17 adults with confirmed past OROV infection (2020) who will be recontacted for follow-up sampling; (2) 50 adults recruited prospectively from a village with ∼80% seroprevalence, aiming to include at least 20 seropositive individuals for robust analysis of antigen-specific B and T cell responses; and (3) an exploratory cohort of 1 to 10 newly confirmed OROV cases identified during the study period in the Cayenne region, enrolled during the convalescent phase (≥1 month post-diagnosis) to complement the immunological analyses conducted in the first two populations.
A 20 ml blood sample is collected, along with data collection (mainly health data), at the time of enrollment.
The study involves: (1) confirming past OROV infection by detecting OROV-specific polyclonal antibodies in plasma; and (2) characterizing OROV-specific B and T cell responses. Key methodological steps include: isolation of OROV-specific B cells by flow cytometry followed by single-cell culture and stimulation to generate human monoclonal antibodies; screening of secreted mAbs against OROV antigens combined with VDJ sequencing to characterize immunoglobulin repertoires; and structural characterization of neutralizing mAbs using cryo-electron microscopy and nano-imaging to identify conserved epitopes.
Institut Pasteur is the lead sponsor of 99 studies on the registry; 41 are open to participants now.
Counted across the registry records on this site, refreshed daily.
The study population lives in French Guiana in 3 different areas (Saül, Trois Sauts, and Cayenne and its surroundings), and eligible individuals (Populations 1 and 3) or those residing in a high-seroprevalence geographic area (Population 2) were identified by the National Reference Center (CNR) for Arboviruses at the Institut Pasteur of French Guiana (IPG) as part of arbovirus virological surveillance in French Guiana.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
For all:
Study population 1:
- Presenting a laboratory-confirmed OROV infection, defined by a positive real-time RT-PCR and/or positive seroneutralization performed as part of the management of and response to the 2020 OROV epidemic in Saül.
Study population 2:
- Residing in Trois-Sauts for at least 5 years
Study population 3:
- Presenting a laboratory-confirmed OROV infection, defined by a positive real-time RT-PCR and/or positive seroneutralization, identified in the Cayenne area and surrounding localities during the study period, as part of the surveillance activities of the CNR for Arboviruses (IPG).
Exclusion Criteria:
For all:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Other: 20 ml blood sample
Other: 20 ml blood sample
Other: 20 ml blood sample
A 20-ml blood sample
Characterization of the adaptive immune response to OROV infection during the convalescent phase.
OROV-specific polyclonal antibodies will be detected in participants' plasma to confirm prior infection.
Time frame: 12 months
Isolate OROV-specific B cells (recognizing the Gn_Gc antigenic complex) and generate human monoclonal antibodies by single B cell culture.
Isolation of OROV-specific B cells by flow cytometry, followed by culture and stimulation of single B cells to generate and identify human monoclonal antibodies specific to OROV.
Time frame: 12 months
Screening of secreted mAbs using OROV antigens and VDJ sequencing to characterize immunoglobulin repertoires.
secreted mAbs using OROV antigens and VDJ sequencing will be screened to characterize immunoglobulin repertoires.
Time frame: 12 months
Structural characterization of neutralizing mAbs by cryo-EM and nano-imaging to identify conserved epitopes.
cryo-EM and nano-imaging will be performed on neutralizing mAbs to characterize structurally the mAbs
Time frame: 12 months
No study locations are listed for this record.
Start is estimated for Nov 2026; primary completion for Dec 2027, 13 months later.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Bunyaviridae Infections