An observational study in Invasive Non-Typhoidal Salmonella Disease, Malaria and Malaria Vaccine, sponsored by International Vaccine Institute. Recruiting at 1 site in Democratic Republic of the Congo. Per ClinicalTrials.gov, last updated 2026-02-18.
Sponsored by International Vaccine Institute · Observational
The goal of this observational study is to learn about the impact of malaria vaccination on the risk of invasive non-typhoidal Salmonella disease in children below the age of 5. Eligible participants residing in the Kisantu Health Zone (DRC) and presenting fever are enrolled in healthcare facilities and tested for malaria and iNTS. Using a case-control (test-negative) design, the researchers will look at the malaria vaccination status of participants with and without iNTS infection to determine if the malaria vaccine protects against iNTS.
1,184 studies on the registry are indexed under Malaria; 79 are open to participants now.
This study's planned enrollment of 10,000 is above the median of 582 across 204 observational studies indexed under Malaria.
Browse Malaria studies →International Vaccine Institute is the lead sponsor of 47 studies on the registry; 12 are open to participants now.
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Though only children 6-24 months of age are eligible to receive R21/Matrix-M, patients of all age groups presenting with fever at participating sites will be monitored for malaria and iNTS.
Inclusion Criteria:
Depending on the study objective, participants who received at least the three primary doses of the R21/Matrix-M vaccine will be considered for analysis (complete vaccination - primary objective) or participants who received either the first or first two doses of R21/Matrix-M vaccine (incomplete vaccination - secondary objectives) shall be considered for analysis.
Biological: R21/Matrix-M malaria vaccine
Unvaccinated participants will be defined as not meeting the definitions for complete nor incomplete vaccination by time of enrollment.
R21/Matrix-M malaria vaccination was introduced by DRC Ministry of Public Health in the Expanded Program on Immunizations on 29th of October 2024. Children aged 6 months to 24 months are eligible to receive the vaccine. Vaccination follows a 4 doses schedule: a first dose administered between 6 and 11 months of age, a second dose one month after the first dose, a third dose one month after the second dose and a booster dose seven months after the third dose.
Blood culture-confirmed iNTS disease (including malaria co-infections) in participants who received complete malaria vaccination vs. unvaccinated participants.
Among individuals seeking care for symptoms consistent with clinical malaria/iNTS, those who have received the full recommended regimen of the R21/Matrix-M malaria vaccine will have a 1.00 - 0.38 or lower odds of blood-culture confirmed iNTS.
Time frame: At presentation (enrollment)
Blood culture-confirmed iNTS disease (including malaria co-infections) in participants who received any dose of malaria vaccine vs. unvaccinated participants.
Among individuals seeking care for symptoms consistent with clinical malaria/iNTS, those who have received any dose of the R21/Matrix-M malaria vaccine will have a 1.00 - 0.19 or lower odds of blood-culture confirmed iNTS.
Time frame: At presentation (enrollment)
Culture-confirmed iNTS disease (including malaria co-infections) in participants with at least one severity feature and who received complete malaria vaccination vs. unvaccinated participants.
Among individuals seeking care for symptoms consistent with clinical malaria/iNTS and meeting the definition for severe disease at first presentation to the enrolling healthcare facility, those who have received the full recommended regimen of the R21/Matrix-M malaria vaccine will have a 1.00 - 0.57 or lower odds of blood-culture confirmed iNTS.
Time frame: At presentation (enrollment)
Blood culture-confirmed iNTS disease (including malaria co-infections) in participants with at least one severity feature and who received any dose of the malaria vaccine vs. unvaccinated participants.
Among individuals seeking care for symptoms consistent with clinical malaria/iNTS and meeting the definition for severe disease at first presentation to the enrolling healthcare facility, those who have received any dose of the R21/Matrix-M malaria vaccine will have a 1.00 - 0.38 or lower odds of blood-culture confirmed iNTS.
Time frame: At presentation (enrollment)
mRDT, blood smear and/or PCR-confirmed malaria disease, including severe malaria cases, with or without culture-confirmed iNTS disease, in participants who received complete malaria vaccination vs. unvaccinated participants
Among individuals seeking care for symptoms consistent with clinical malaria/iNTS, those who have received the full recommended regimen of the R21/Matrix-M malaria vaccine will have a 1.00 - 0.75 or lower odds of test-positive malaria infection.
Time frame: At presentation (enrollment)
Impact of vaccination using R21/Matrix-M on the incidence of culture-confirmed iNTS and mRDT, blood smear and/or PCR confirmed malaria co-infection (before/after)
Among individuals seeking care for symptoms consistent with clinical malaria/iNTS (age-cohorts exposed to R21/Matrix-M vaccination program), relative rate of healthcare-ascertained, laboratory-confirmed malaria-iNTS co-infections 1-year-after versus before the introduction of the program will be 1.00 - 0.38 or lower.
Time frame: 2 years
Plan to share: Undecided
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