An observational study in Malaria, sponsored by National Institute of Allergy and Infectious Diseases (NIAID). Active, not recruiting at 1 site in Liberia. Open to participants aged 6 Months and older. Per ClinicalTrials.gov, last updated 2026-01-16.
Sponsored by National Institute of Allergy and Infectious Diseases (NIAID) · Observational
Background:
Malaria is a disease that affects many people in Liberia. It is caused by germs (parasites) that are spread by mosquito bites. Researchers want to gather data that may help them understand the best way to use a malaria vaccine in Liberia, which will be important in getting rid of the disease.
Objective:
To find out how often people of all ages who live in Fleh-la and Marshansue, Liberia, get malaria.
Eligibility:
Healthy people ages 6 months and older who live in Fleh-la and Marshansue in a household with adults and children.
Design:
Participants will be screened with a physical exam and questions about their health.
Participants will have monthly study visits. They will be asked about any symptoms of malaria and their use of bednets. Their vital signs, such as blood pressure and temperature, will be checked. Blood will be taken from the participant s arm or finger with a needle. If they have a fever, they will get a malaria test. If positive, they will get drugs to treat malaria.
Once a month, participants houses will be examined for mosquitoes. The team will remove all mosquitoes they collect. As part of this collection, participants houses will be sprayed with a chemical to kill mosquitoes and other insects. Participants will not be allowed in their house while the team is inside. The spray will not harm the participants.
Once a year, at the monthly visit, an additional blood sample will be taken.
Some of the participants blood samples will be used for genetic testing.
Participation will last for up to 3 years.
A vaccine that interrupts malaria transmission is critical to eradicate the disease, but improved assays are needed to measure the efficacy of vaccines. Transmission-blocking vaccines (TBVs) work by inducing antibodies that inhibit parasite development in the mosquito interrupting transmission. Efficacy of vaccines may be estimated by in vitro membrane feeding assays using immune sera and laboratory mosquitoes, but qualified assays that measure transmission in the field are needed to assess transmission-blocking interventions in natura. Clinical trials of TBVs have started elsewhere on the continent in Mali, and we have planned to expand TBV studies here in Liberia soon. This protocol is already being used for a longitudinal cohort to gather information of malaria transmission based on the rates of blood smear positive individuals by month, season and year in Fleh-la and Marshansue, in Salala, Bong County, Liberia. Individuals in the villages were approached first for participation, including permission to contact their household and neighbors of their compound for participation. Households were identified using census data and individuals who consented for participation are being enrolled. Malaria smears are obtained at monthly visits, in conjunction with mosquito collections in/around village residences. Parasite infection rates in locally caught mosquitoes will be assessed longitudinally for differences by season and year. A total of 400 volunteers from Fleh-la and Marshansue will be enrolled. Participants will be followed for at least one year, to collect data that will guide the design of future community-based trials of TBV for which this amendment is being submitted for approval.
1,184 studies on the registry are indexed under Malaria; 79 are open to participants now.
This study's enrollment of 396 is below the median of 582 across 204 observational studies indexed under Malaria.
Browse Malaria studies →National Institute of Allergy and Infectious Diseases (NIAID) is the lead sponsor of 2,446 studies on the registry; 179 are open to participants now.
Of its 405 completed or terminated interventional studies of FDA-regulated products, 302 (75%) have results posted.
Counted across the registry records on this site, refreshed daily.
An estimated total of 400 volunteers from Fleh-la and Marshansue and surrounding villages will be enrolled. Participants above the age of six months will be approached to participate in the study; and will be followed for up to 3 years.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Subject Inclusion Criteria:
Household Inclusion Criteria:
To be eligible for participation, households must meet the following criteria:
Exclusion Criteria:
Subject Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Age bracket for infants/children up to age five years
Age bracket for children 10 - 18 years
Age bracket for adults over 19 years
Age bracket for children ages 5 - 10 years
Measurement of Monthly rates of blood smear positive individuals by age
Rate of blood smear positive individuals
Time frame: one year
Plan to share: No
No publications or documents are linked to this record.
Ran from Sep 2021 to primary completion in Apr 2023, 18 months.
Of 85 non-industry observational studies under Malaria, half reached primary completion within 23 months of starting (the median), counting those still running; a quarter within 13 and three quarters within 36. This study's 18 months is below that.
Counting every sponsor, half of 93 studies reached it within 24 months; a quarter within 16 and three quarters within 44.
How these figures are worked out, and which studies are left out of them.
This study is active, not recruiting, as verified in Jan 2026. You cannot join it, but the record below documents what was studied.
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National Institute of Allergy and Infectious Diseases (NIAID) →