NCT07320716

Long-Term Immunogenicity of the altSonflex1-2-3 Shigella Vaccine in African Children

A Phase 2, Open-Label, Single-Center, Long-Term Immunogenicity Follow-Up Study of the GVGH altSonflex1-2-3 Shigella Vaccine 1, 2 and 3 Years After Vaccination in African Children

• Status: Not Yet Recruiting
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 528 (estimated)
• Sponsor: GlaxoSmithKline · Industry
• Sex: All
• Age: 26 Months – 55 Months
• Healthy volunteers: Accepted

Summary

The current study is a follow-up to 2 previous parent studies, a dose-selection study with 3 different dose-levels of the altSonflex1-2-3 vaccine in a schedule of 3 vaccinations (H06\_01TP study \[NCT05073003, 212149\]) and a study with an alternate 2 vaccination schedule H06\_02TP study \[NCT06663436, 219449\]). The current study aims to assess the longevity of the immune response to the selected dose of the altSonflex1-2-3 vaccine 1, 2, and 3 years after the last vaccination in African children. The study involves no new vaccinations but will collect immunogenicity blood samples from participants.

Conditions

• Diarrhoea

Interventions

Type	Name	Description
BIOLOGICAL	AltSonflex1-2-3	No intervention is administered in this extension study. The selected dose of altSonflex1-2-3 vaccine was administered intramuscularly in the participants' thigh during the H06\_01TP (212149) parent study on Day 1, Day 85, and Day 253; or on Day 1 and Day 169 during the H06\_02TP (219449) study.
BIOLOGICAL	Menveo	No intervention is administered in this extension study. The Menveo vaccine was administered intramuscularly in the participants' thigh on Day 1 and Day 85 during the H06\_01TP (212149) parent study.
BIOLOGICAL	Infanrix hexa	No intervention is administered in this extension study. The Infanrix hexa vaccine was administered intramuscularly in the participants' thigh on Day 281 during the H06\_01TP (212149) study; or on Day 169 during the H06\_02TP (219449) parent study.
BIOLOGICAL	TYPHIBEV	No intervention is administered in this extension study. The TYPHIBEV vaccine was administered intramuscularly in the participants' thigh on Day 1 during the H06\_02TP (219449) parent study.

Timeline

• Start date: 2026-01-02
• Primary completion: 2028-10-31
• Completion: 2028-10-31
• First posted: 2026-01-06
• Last updated: 2026-01-06