Characterization of Human Immune Signatures to Zoonotic Virus Exposure in Cambodia

NCT06680843 | Recruiting

• 1 other identifier: 002014
• Study Type: observational
• Target: 400
• Locations: 1 country
• Sites: 5

Brief Summary

This is a biospecimen procurement protocol to characterize the immune response to zoonotic virus exposure in healthy adult humans aged 18 to 65 years with high-risk exposure to animals or their excreta (e.g., guano farming and wet markets), or living within 5 km of animal habitats (e.g., bat caves and bat roosts) in Cambodia.

Conditions

Immunity, Humoral

Outcome Measures

Primary Outcomes (3)

• Antibody binding activity in plasma samples against known immunodominant zoonotic viral proteins

  Measured by binding antibody titer greater than cutoffs established from healthy U.S. donors (3 standard deviations above mean signal intensity) to a panel of either henipaviruses, influenza viruses, or sarbecoviruses

  Day 0 and 2 optional visits at least 30 days apart between Day 180-720

• Neutralizing activity of plasma samples against known immunodominant zoonotic viral proteins

  Measured by circulating antigen-specific B cells constituting approximately 0.001%-0.005% total PBMCs

  Day 0 and 2 optional visits at least 30 days apart between Day 180-720

• Isolate viral antigen-specific B cells for phenotyping and immunoglobulin sequencing

  Measured by isolation of an expected 20 million PBMCs from whole blood samples, yielding approximately 100-500 antigen-specific B cells for single-cell B-cell sequencing (anticipated cell death up to 50% during the isolation and sorting process)

  Day 0 and 2 optional visits at least 30 days apart between Day 180-720

Interventions

Whole blood collection PROCEDURE

30 mL at Day 0 with optional visits for up to 2 additional whole blood collections at least 30 days apart

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Healthy adults aged 18 to 65 years who handle suspected infected animals or their excreta, or living within 5 km of animal reservoirs, in Cambodia (n=160 to 320).

You may qualify if:

• Capacity to provide informed consent.
• Adult aged 18-65 years.
• Have interaction with suspected infected animals within the last 2 years, including (but not limited to) the following risk factors:
• Hunting, slaughtering, or consuming suspected infected animals;
• Fruit collection, date palm sap harvesting, or tree pruning within agricultural plantations containing bat roosts;
• Bat guano farming;
• Ancillary work in live animal markets or wild animal habitats identified as likely containing infected animals (e.g., provision of cleaning, transportation, or tourism services);
• Living within 5 km of identified animal markets or wild animal habitats identified as likely containing infected animals.
• Willing to allow biological samples and data to be stored for future research.

You may not qualify if:

• Pregnancy (based on self-reporting).
• Any underlying, chronic, or current medical condition that, in the opinion of the investigator, would interfere with participation in the study (e.g., inability or great difficulty in drawing blood, known anemia).
• Self-reported symptoms suggestive of acute infection (acute myalgias, arthralgias, headache, retro-orbital pain, dyspnea, rash) within 7 days prior to enrollment.
• Signs suggestive of acute infection (fever, defined as internal temperature \>38°C; hypoxemia, defined as peripheral oxygen saturation of \<90%; hypotension, defined as systolic blood pressure \<90 mm Hg or diastolic blood pressure \<50 mm Hg) present at screening.
• Self-reported diagnosis of immune deficiency, including HIV infection, chronic corticosteroid use (≥10 mg prednisone dose or its equivalent for a continuous period of ≥30 days within the last 1 year), ongoing or prior (within the last 10 years) receipt of chemotherapy or immunotherapy, or current hematological malignancy.
• Receipt of blood products, including immunoglobulin products, within 120 days of study enrollment.

Sponsors & Collaborators

• National Institute of Allergy and Infectious Diseases (NIAID): lead

Study Sites (5)

Communicable Disease Control Department

Battambang, Cambodia

RECRUITING

Communicable Disease Control Department

Kampong Thom, Cambodia

RECRUITING

Communicable Disease Control Department

Kampot, Cambodia

RECRUITING

Communicable Disease Control Department

Stung Treng, Cambodia

RECRUITING

Communicable Disease Control Department

Takeo, Cambodia

RECRUITING

Biospecimen

Retention: SAMPLES WITH DNA

Whole blood

Study Officials

• Christina Yek, MD

  NIH/NIAID/Laboratory of Malaria and Vector Research (LMVR)

  PRINCIPAL INVESTIGATOR

• Lon Chanthap, MD

  Malaria Vector & Research Laboratory (MVRL) International Center of Excellence in Research Cambodia

  PRINCIPAL INVESTIGATOR

• Ly Sovann, MD, MTCM

  Cambodian Center for Communicable Disease (CCDC) Ministry of Health, Cambodia

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Chanthap Lon, MD

CONTACT

85512976799; lonc@icercambodia.org

Study Design

• Study Type: observational
• Observational Model: ECOLOGIC OR COMMUNITY
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: NIH
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 6, 2024
• First Posted: November 8, 2024
• Study Start: November 1, 2024
• Primary Completion (Estimated): October 31, 2027
• Study Completion (Estimated): May 1, 2028
• Last Updated: May 6, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, CSR
• Time Frame: 5 years following completion of the primary endpoint
• Access Criteria: Researchers should contact the Principal Investigators with data requests.

Locations

CA (5)