Clinical Research Directory

Immunogenicity and Tolerability of Booster Typhoid Conjugate Vaccine (TCV) 5-6 Years After Initial Dose in Children in Burkina Faso

This study evaluated the persistence of immunity following primary typhoid conjugate vaccination in early childhood and assessed the immunogenicity and safety of a booster dose administered 5-6 years later. Children previously enrolled in a Phase 2 randomized clinical trial of Vi-tetanus toxoid conjugate vaccine (Vi-TT) were re-enrolled at 6-7 years of age. Participants who previously received Vi-TT received a booster dose of Vi-CRM, while control participants received their first TCV dose. Anti-Vi IgG antibody responses were measured at baseline and 28 days post-vaccination. Safety was assessed through solicited and unsolicited adverse events. This study provides data on durability of TCV immunity and the potential role of booster dosing in endemic settings.

Clinical Efficacy of Typhoid Conjugate Vaccine (Vi-TCV) Among Children Age 9 Months Through 12 Years in Blantyre, Malawi

This study will evaluate the efficacy of a Typhoid conjugate vaccine (Vi-TCV) in Malawi, Africa among children age 9 months through 12 years. Participants will be randomized in a 1:1 ration to receive the study vaccine or the control vaccine (meningococcal group A conjugate vaccine - MCV-A).

Transcriptomic Responses for the Identification of Pathogens

Acute undifferentiated febrile infection (AUFI) is a common presenting syndrome in low-resource settings and better diagnostics are urgently needed to improve patient management and guide disease prevention interventions. Assessment of the host gene expression response to infection in endemic populations has demonstrated significant promise as a new approach to identifying patients with enteric fever and for potential in differentiating between other causes of AUFI. Signatures identified through new data analytic techniques could be developed into a point-of-care test for use in endemic settings. In this multisite diagnostic evaluation study we will collect prospective clinical, laboratory and diagnostic data from two endemic settings to evaluate host gene expression signatures for detecting enteric fever and for determining the cause of AUFI in LMIC settings.

ZyVac-TCV Bangladesh Study

This is a prospective closed cohort, open-label, phase III effectiveness study using a test-negative design of a typhoid conjugate vaccine, ZyVac® TCV (purified Vi capsular polysaccharide of Salmonella Typhi conjugated to tetanus toxoid as carrier protein), manufactured by Zydus Lifesciences Limited. The study will be conducted in a closed cohort population among children aged 6 months to 15 years residing in wards 5, 6, 7, 48, 49, 50, 63, 71, and 72 of Dhaka South City Corporation (DSCC). The targeted number of age-eligible children in the study area is \~92,000 among them \~60,000 will be vaccinated. A subset of the first 600 consenting participants will be selected by age strata (6 months to \<2 years, 2-4 years, 5-15 years) for enrollment in the immunogenicity study with an additional three follow-up visits. Diary cards will be used to collect adverse events (AEs) following immunization (AEFI) data up to day 7 for a subset of active follow-up of the first 600 vaccinated participants. Participants not in this subset will be encouraged to go to the 'Adverse Event Monitoring Cell' at the Maniknagar field office. Data on serious adverse events (SAEs) will be reported for six months after vaccination. All study updates including AEs and SAEs will be reported to the data safety and monitoring board (DSMB) and sponsor. Passive surveillance for typhoid fever will be carried out in the Maniknagar field office and Mugda Medical College and Hospital in the catchment area among the age-eligible children.