A Study to Evaluate the Safety, Reactogenicity, and Immune Response of the GSK Vaccines Institute for Global Health (GVGH) Quadrivalent Pan-Salmonella Vaccine With and Without Alum in Healthy Young Adults

A Phase 1, Randomized, Controlled, Observer-blind Study to Evaluate the Safety, Reactogenicity, and Immunogenicity of the GVGH Quadrivalent Pan-Salmonella Vaccine With and Without Alum in Healthy Adults 18 to 45 Years of Age in Africa

The current clinical study will evaluate the GVGH Quadrivalent Pan-Salmonella vaccine for the first time in healthy adults in Africa. The purpose of the current Phase 1 study is to evaluate the safety, reactogenicity, and the immune response induced by the Pan-Salmonella vaccine.

Study Overview

• Status: Not yet recruiting
• Conditions: Salmonella Infections
• Intervention / Treatment: Biological: Pan-Salmonella-with-Alum (Low dose) vaccine; Biological: Pan-Salmonella-with-Alum (Full dose) vaccine; Biological: Pan-Salmonella-without-Alum (Low dose) vaccine; Biological: Pan-Salmonella-without-Alum (Full dose) vaccine; Biological: Typhoid Vi conjugate vaccine; Other: Placebo

• Study Type: Interventional
• Enrollment (Estimated): 196
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: US GSK Clinical Trials Call Center; Phone Number: 877-379-3718; Email: GSKClinicalSupportHD@gsk.com
• Study Contact Backup: Name: EU GSK Clinical Trials Call Center; Phone Number: +44 (0) 20 89904466; Email: GSKClinicalSupportHD@gsk.com

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Participants who, in the opinion of the Investigator, can and will comply with the requirements of the protocol (e.g., completion of the Diary cards, return for follow-up visits).
2. Written informed consent obtained from the participant prior to performance of any study specific procedure.

3. Healthy participants as established by medical history, clinical examination, and laboratory assessment*.

   *Hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV) antibodies, and human immunodeficiency virus (HIV) antibodies will also be tested at Screening.

4. A male or female between and including 18 to 45 years of age at the time of the first study intervention administration, and no older than 45 years of age at second dose administration.
5. Female participants of nonchildbearing potential may be enrolled in the study. Nonchildbearing potential is defined as pre-menarche, current bilateral tubal ligation or occlusion, hysterectomy, bilateral ovariectomy, or menopause.

6. Participants of childbearing potential may be enrolled in the study if the participant:

   • Has practiced adequate contraception (as indicated in Section 10.5) for at least 30 days prior to study intervention administration, and
   • Has a negative pregnancy test within 24 hours prior to the study intervention administration, and
   • Has agreed to continue adequate contraception during the entire treatment period and for 8 weeks after completion of the study intervention administration series.
7. Negative HLA-B27 testing.
8. Body mass index of 18>= to <=30 kg/m2 at Screening.
9. Living in the study area and plan to remain in the study area for the study duration.

Exclusion Criteria:

Medical Conditions:

1. Known exposure to S. Typhi, S. Paratyphi A, and non-typhoidal Salmonella confirmed by blood culture during the period starting 3 years prior to first study intervention administration as confirmed using medical history.
2. History of any reaction or hypersensitivity likely to be exacerbated by any component of the study intervention.
3. Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination (no laboratory testing required).
4. Acute or chronic clinically significant pulmonary, cardiovascular, hepatic, or renal functional abnormality, as determined by physical examination or laboratory screening tests.
5. Recurrent history or uncontrolled neurological disorders or seizures.
6. Any clinically significant hematological and/or biochemical laboratory abnormality.
7. Clinical conditions representing a contraindication to intramuscular (IM) injections and/or blood draws.
8. Any behavioral or cognitive impairment or psychiatric disease that in the opinion of the Investigator, may interfere with the participant's ability to participate in the study.
9. Acute or chronic illness which may be severe enough to preclude participation.

10. Any other clinical condition that, in the opinion of the Investigator, might pose additional risk to the participant due to participation in the study.

    Prior/Concomitant Therapy:

11. History of receiving any typhoid vaccine (Ty21a, Vi capsular polysaccharide, or TCV) in the participant's life.
12. History of receiving any investigational iNTS, S. Paratyphi A, or GMMA vaccines in the participant's life.

13. Use of any investigational or non-registered product (drug, vaccine, or medical device) other than the study interventions during the period beginning 30 days (Days -30 to 1) before the first dose of study interventions, or their planned use during the study period.

    Use of herbs and traditional treatments is not considered an exclusion criterion.

14. A vaccine not foreseen by the study protocol administered during the period starting at 14 days before the first dose and ending 30 days after the last dose of study interventions administration, with the exception of flu vaccines or Coronavirus disease 2019 vaccine.
15. Administration of long-acting immune-modifying drugs (e.g., infliximab) at any time during the study period.
16. Administration of immunoglobulins and/or any blood products or plasma derivatives during the period starting 3 months before the administration of the first dose of study interventions or planned administration during the study period.

17. Chronic administration (defined as more than 14 days in total) of immunosuppressants or other immune-modifying drugs during the period starting 3 months prior to the first study intervention dose(s). For corticosteroids, this will be prednisone equivalent >=20 mg/day for adult participants. Inhaled and topical steroids are allowed.

    Prior/Concurrent Clinical Study Experience:

18. Concurrently participating in another clinical study, at any time during the study period, in which the participant has been or will be exposed to an investigational or a non-investigational intervention (vaccine and drug).

    Other Exclusions:

19. Pregnant or lactating female.
20. Female planning to become pregnant or planning to discontinue contraceptive precautions.
21. History of/current chronic alcohol consumption and/or drug abuse. This will be decided at the discretion of the Investigator.
22. Any study personnel or their immediate dependents, family, or household members.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Sequential Assignment
• Masking: Triple

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Pan-Salmonella with Alum (Low dose) Group; Participants will receive the low dose level of the candidate Pan-Salmonella-with-aluminium-hydroxide (Alum) vaccine at Days 1, 61 and 181.	Biological: Pan-Salmonella-with-Alum (Low dose) vaccine; Participants receive low dose of the Pan-Salmonella-with-Alum.
Experimental: Pan-Salmonella with Alum (Full dose) Group; Participants will receive the full dose level of the candidate Pan-Salmonella-with-Alum vaccine at Days 1, 61 and 181.	Biological: Pan-Salmonella-with-Alum (Full dose) vaccine; Participants receive full dose of the Pan-Salmonella-with-Alum.
Experimental: Pan-Salmonella without Alum (Low dose) Group; Participants will receive the low dose level of the candidate Pan-Salmonella-without-Alum vaccine at Days 1, 61 and 181.	Biological: Pan-Salmonella-without-Alum (Low dose) vaccine; Participants receive low dose of the Pan-Salmonella-without-Alum.
Experimental: Pan-Salmonella without Alum (Full dose) Group; Participants will receive the full dose level of the candidate Pan-Salmonella-without-Alum vaccine at Days 1, 61 and 181.	Biological: Pan-Salmonella-without-Alum (Full dose) vaccine; Participants receive full dose of the Pan-Salmonella-without-Alum.
Placebo Comparator: Control Group; Participants will receive placebo at Days 1 and 181, and Typhoid Vi conjugate vaccine at Day 61.	Biological: Typhoid Vi conjugate vaccine; Participants receive Typhoid Vi conjugate vaccine as control; Other Names: TYPHIBEV; Other: Placebo; Participants receive Placebo (saline solution) as control.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of participants with solicited administration site events	Assessed solicited administration site events will be pain, redness and swelling.	From Day 1 to Day 7
Number of participants with solicited administration site events		From Day 61 to Day 67
Number of participants with solicited administration site events		From Day 181 to Day 187
Number of participants with solicited systemic events	Assessed solicited systemic events will be fever, headache, myalgia, arthralgia and fatigue.	From Day 1 to Day 7
Number of participants with solicited systemic events		From Day 61 to Day 67
Number of participants with solicited systemic events		From Day 181 to Day 187
Number of participants with unsolicited events	An unsolicited adverse event (AE) is an AE that was either not included in the list of solicited AEs, or could. be included in the list of solicited AEs but with an onset outside the specified period of. follow-up for solicited AEs. Unsolicited AEs must have been communicated by participants who have signed informed consent. Unsolicited AEs include serious and non-serious AEs.	From Day 1 to Day 30
Number of participants with unsolicited events		From Day 61 to Day 91
Number of participants with unsolicited events		From Day 181 to Day 211
Number of participants with serious adverse events (SAEs)	An SAE is defined as any untoward medical occurrence that, at any dose, results in persistent or significant disability/incapacity, requires inpatient hospitalization or prolongation of existing hospitalization, is life-threatening, or results in death.	From Day 1 to Day 211
Number of participants with adverse events (AEs) or SAEs leading to withdrawal from the study or discontinuation of study intervention		From Day 1 to Day 211
Number of participants with changes from baseline or changes from normal values for hematological, renal, and hepatic panels test results		At Day 8
Number of participants with changes from baseline or changes from normal values for hematological, renal, and hepatic panels test results		At Day 68
Number of participants with changes from baseline or changes from normal values for hematological, renal, and hepatic panels test results		At Day 188

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of participants with serious adverse events (SAEs)		From Day 211 to Day 361
Number of participants with AEs/SAEs leading to withdrawal from the study or discontinuation of study intervention		From Day 211 to Day 361
Geometric mean concentration (GMC) of anti-serotype specific immunoglobulin G (IgG) antibody	The GMC will be determined using Enzyme-linked immunosorbent assay (ELISA).	Pre-intervention at Day 1, Day 61 and Day 181
Adjusted GMC of anti-serotype specific IgG antibody		Pre-intervention at Day 1, Day 61 and Day 181
GMC of anti-serotype specific IgG antibody		At Day 31, Day 91 and Day 211
Adjusted GMC of anti-serotype specific IgG		At Day 31, Day 91 and Day 211
Number of participants with anti-serotype specific IgG antibody concentration fold increase	At least a 4-fold rise will be evaluated.	At Day 31, Day 91 and Day 211 compared with baseline (Day 1)
Number of participants with Anti-Vi Ag IgG antibody concentrations	The concentration considered will be equivalent to ≥4.3 microgram per milliliter (μg/mL).	Pre-dose at Day 1, Day 61 and Day 181
Number of participants with Anti-Vi Ag IgG antibody concentrations	The concentration considered will be equivalent to ≥4.3 μg/mL	At Day 31, Day 91 and Day 211
Number of participants with Anti-Vi Ag IgG antibody concentrations	The concentration considered will be ≥2.0 μg/mL	Pre-dose at Day 1, Day 61 and Day 181
Number of participants with Anti-Vi Ag IgG antibody concentrations	The concentration considered will be ≥2.0 μg/mL.	At Day 31, Day 91 and Day 211

Collaborators and Investigators

• Sponsor: GlaxoSmithKline

Study record dates

Study Major Dates

• Study Start (Estimated): June 24, 2026
• Primary Completion (Estimated): November 14, 2027
• Study Completion (Estimated): November 14, 2027

Study Registration Dates

• First Submitted: June 17, 2026
• First Submitted That Met QC Criteria: June 17, 2026
• First Posted (Actual): June 23, 2026

Study Record Updates

• Last Update Posted (Actual): June 23, 2026
• Last Update Submitted That Met QC Criteria: June 17, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Safety; Immunogenicity; Reactogenicity; GVGH Quadrivalent Pan-Salmonella vaccine; Salmonella (S.) Typhi; S. Paratyphi A; S. Typhimurium (STm); S. Enteritidis (SEn)
• Additional Relevant MeSH Terms: Infections; Bacterial Infections; Bacterial Infections and Mycoses; Gram-Negative Bacterial Infections; Enterobacteriaceae Infections; Salmonella Infections; Biological Products; Complex Mixtures; Vaccines
• Other Study ID Numbers: 300281

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Study Sponsor will assess requests from qualified researchers for anonymized individual patient-level data and related study documents. Data sharing is subject to certain criteria, conditions, and exceptions. For further information, refer to https://www.gsk-studyregister.com/gsk-patient-level-data-sharing-july2025.pdf
• IPD Sharing Time Frame: Anonymized IPD will be made available within 6 months of publication of primary, key secondary and safety results for studies in product with approved indication(s) or asset(s) with development terminated across all indications.
• IPD Sharing Access Criteria: Anonymized IPD is shared with researchers whose proposals are approved by an Independent Review Panel and after a Data Sharing Agreement is in place. Access is provided for an initial period of 12 months, but an extension may be granted, when justified, for up to 6 months.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No