Inflammatory Challenge and Fear

NCT06630884 | Recruiting Phase 1 DMC FDA Drug

• 1 other identifier: R01MH135076
• Study Type: interventional
• Target: 288
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this study is to learn if short-term changes in the immune system alter how we process information and experience fear. The main questions it aims to answer are: Do people who receive typhoid vaccine respond differently than those who receive a placebo saline vaccine? Do people who receive typhoid vaccine experience changes in how they think and feel? Participants will: Attend four appointments at the San Francisco VA Health Care System; Receive typhoid vaccine or placebo at one of the visits; Have their physiological responding measured while listening to sounds; Complete questionnaires and psychological tests.

Conditions

Posttraumatic Stress Disorder (PTSD)

Keywords

PTSD; posttraumatic stress; inflammation; fear

Outcome Measures

Primary Outcomes (1)

• Skin conductance response (SCR)

  Skin conductance level (SCL)will be sampled at 1000 Hz beginning 2 s prior to the conditioned stimulus (CS) onset and continuing until 6 s following CS offset. The skin conductance response (SCR) score for each CS interval will be obtained by subtracting the mean SCL for the 2 s preceding CS onset from the peak during the 8 s CS interval.

  SCR will be assessed at baseline, 4.5 hours, and one week after vaccine/placebo.

Secondary Outcomes (2)

• Heart rate

  HR will be assessed at baseline, 4.5 hours, and one week after vaccine/placebo.

• Eyeblink electromyography (EMG)

  Eyeblink EMG will be assessed at baseline, 4.5 hours, and one week after vaccine/placebo.

Study Arms (2)

Polysaccharide typhoid vaccine

EXPERIMENTAL

Participants in this condition will receive an injection of 0.5ml Salmonella typhi capsular polysaccharide vaccine (Sanofi Pasteur, SA), which contains 25μg of purified Vi polysaccharide in a colorless isotonic phosphate buffered saline (pH 7±0.3), 4.150mg of sodium chloride, 0.065mg of disodium phosphate, 0.023mg of monosodium phosphate and 0.5ml of sterile water for injection.

Biological: Typhoid VI Polysaccharide Vaccine Injectable Solution

Saline Placebo Arm

PLACEBO COMPARATOR

Participants in this condition will receive and injection of 0.5ml of saline.

Other: Saline Placebo (0.5mL injection)

Interventions

Typhoid VI Polysaccharide Vaccine Injectable Solution BIOLOGICAL

Salmonella typhi capsular polysaccharide vaccine (Typhoid Vi Polysaccharide Vaccine): Each dose of 0.5ml Salmonella typhi capsular polysaccharide vaccine (Sanofi Pasteur, SA) is formulated to contain 25μg of purified Vi polysaccharide in a colorless isotonic phosphate buffered saline (pH 7±0.3), 4.150mg of sodium chloride, 0.065mg of disodium phosphate, 0.023mg of monosodium phosphate and 0.5ml of sterile water for injection. It is indicated for use by humans aged 2 years and older for protection against typhoid fever.

Polysaccharide typhoid vaccine

Saline Placebo (0.5mL injection) OTHER

The placebo injection will consist of 0.5mL of saline.

Saline Placebo Arm

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• All Subjects:
• Aged 18-60 years old
• Trauma Exposed
• Current PTSD/No history of PTSD

You may not qualify if:

• Contraindications to typhoid vaccine
• Conditions associated with inflammation
• Pregnancy or plans to become pregnant in next three months

Sponsors & Collaborators

• National Institute of Mental Health (NIMH): collaborator
• Northern California Institute of Research and Education: collaborator
• San Francisco Veterans Affairs Medical Center: collaborator
• University of California, San Francisco: lead

Study Sites (1)

San Francisco VA Health Care System

San Francisco, California, 94121, United States

RECRUITING

Related Links

• Related Info

MeSH Terms

Conditions

Stress Disorders, Post-Traumatic; Inflammation

Interventions

Injections

Condition Hierarchy (Ancestors)

Stress Disorders, Traumatic; Trauma and Stressor Related Disorders; Mental Disorders; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Drug Administration Routes; Drug Therapy; Therapeutics

Study Officials

• Aoife O'Donovan, PhD

  University of California, San Francisco

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Aoife O'Donovan, PhD

CONTACT

415-221-4810; aoife.odonovan@ucsf.edu

Michael Srouji, BA

CONTACT

415-221-4810

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: October 4, 2024
• First Posted: October 8, 2024
• Study Start: March 28, 2025
• Primary Completion (Estimated): November 1, 2028
• Study Completion (Estimated): November 1, 2028
• Last Updated: December 15, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, ICF

Locations

US (1)