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MalariaNCT01360112

Preventing the Spread of Malaria in Mali

An observational study of Malaria, run by National Institute of Allergy and Infectious Diseases (NIAID) at 1 site in Mali.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

A vaccine which interrupts malaria transmission is a critical tool to achieve the ultimate goal of eradication of this disease. Transmission blocking vaccines work by inducing antibody in vaccinated individuals that inhibits the development of malaria parasites in the mosquito, thus interrupting the cycle of… Read more about this study

Who is it for?
Ages 3 months to 50 yearsHealthy volunteers can take part
Conditions the study is for
Malaria
How many people
816 participants
Where
1 siteMali
Study dates
20 May 2011to 16 Nov 2017
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 3 months to 50 years
  • All sexes
  • Healthy volunteers accepted
  • Child, Adult

Who may be able to join

  • All of the following criteria must be fulfilled for a volunteer to participate in the study:
  • Age between 3 months and 50 years, inclusive
  • Good general health as a result of review of medical history and/or clinical testing at the time of screening
  • Available for the duration of the study (1 year)
  • Willingness to participate in the study as evidenced by signing the informed consent document, or by fingerprinting the consent document with the signature of a witness
  • Known resident of the village of the study
  • Willingness to allow stored laboratory specimens to be used for future research.
  • In addition to the above criteria, the expanded adult cohort must be willing to consider participation in a future malaria vaccine trial.

Who cannot join

  • A volunteer will be excluded from participating in this study if any one of the following criteria is fulfilled:
  • Pregnancy as determined by history or a positive urine Beta-hCG test at any point during the study.
  • Behavioral, cognitive, or psychiatric disease that in the opinion of the investigator affects the ability of the subject to understand and cooperate with the study protocol.
  • Other condition that, in the opinion of the investigator, would jeopardize the safety or rights of a volunteer participating in the trial or would render the subject unable to comply with the protocol.
  • Participation in another investigational vaccine or drug trial while this study is ongoing.
  • Previous receipt of experimental malaria vaccine.
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  • Baseline hemoglobin < 8.5 g/dL
  • In addition to above criteria, a volunteer will be excluded from participating in the transmission blocking assay part of the study if the following criteria is fulfilled:
  • History of reactions to mosquito bites with severe itching or swelling, or lasting longer than 3 days

Trial locations and contacts

1 site in 1 country.

Mali1 site
  • University of Bamako, Faculty of Medicine, Pharmacy and Odontostomatology

    Bamako

Other trials in Mali

About this study

Official title: Malaria Transmission Blocking Assay Development and Gametocyte Carriage in a Vaccine Testing Site in Mali

A vaccine which interrupts malaria transmission is a critical tool to achieve the ultimate goal of eradication of this disease. Transmission blocking vaccines work by inducing antibody in vaccinated individuals that inhibits the development of malaria parasites in the mosquito, thus interrupting the cycle of transmission to the next human host. Efficacy of these vaccines may be estimated by in vitro membrane feeding assays using immune sera and laboratory strain mosquitoes, but these assays need to be qualified to determine to what extent they are predictive of transmission blocking in the field. Clinical trials of transmission blocking vaccines are also anticipated and have started in this community. This protocol will use a nested casecontrol cohort design to compare results of mosquito feeding assays in a malaria exposed population in Bancoumana and surrounding villages in Mali. Households will be identified using census data and individuals will be consented for participation. Malaria smears will be obtained at monthly visits, and gametocytemic individuals will be asked to participate in direct feed experiments using insectary-raised mosquitoes. Infectivity in these mosquitoes will be compared against those of mosquitoes fed in membrane feeding assays in Mali and the USA. Data will also be obtained on gametocyte and parasite carriage rates through the year. A total of 250 volunteers from Bancoumana, ages 3 months to 50 years, were initially enrolled in 2011. In 2012, an additional 250 adults from Bancoumana were enrolled and participants older than 5 years of age who were enrolled in 2011 and wanted to continue participation were re-enrolled into the study. A transmission blocking vaccine trial started in May 2013, and has enrolled participants from this adult cohort in that study. Up to 50 new adults from Bancoumana and surrounding villages will be enrolled in 2014 and those volunteers previously enrolled into the study over theage of 5 years old will be offered re-enrollment into the study.

Read the detailed description

A vaccine which interrupts malaria transmission is a critical tool to achieve the ultimate goal of eradication of this disease. Transmission blocking vaccines work by inducing antibody in vaccinated individuals that inhibits the development of malaria parasites in the mosquito, thus interrupting the cycle of transmission to the next human host. Efficacy of these vaccines may be estimated by in vitro membrane feeding assays using immune sera and laboratory strain mosquitoes, but these assays need to be qualified to determine to what extent they are predictive of transmission blocking in the field. Clinical trials of transmission blocking vaccines are also anticipated and have started in this community. This protocol will use a nested casecontrol cohort design to compare results of mosquito feeding assays in a malaria exposed population in Bancoumana and surrounding villages in Mali. Households will be identified using census data and individuals will be consented for participation. Malaria smears will be obtained at monthly visits, and gametocytemic individuals will be asked to participate in direct feed experiments using insectary-raised mosquitoes. Infectivity in these mosquitoes will be compared against those of mosquitoes fed in membrane feeding assays in Mali and the USA. Data will also be obtained on gametocyte and parasite carriage rates through the year. A total of 250 volunteers from Bancoumana, ages 3 months to 50 years, were initially enrolled in 2011. In 2012, an additional 250 adults from Bancoumana were enrolled and participants older than 5 years of age who were enrolled in 2011 and wanted to continue participation were re-enrolled into the study. A transmission blocking vaccine trial started in May 2013, and has enrolled participants from this adult cohort in that study. Up to 50 new adults from Bancoumana and surrounding villages will be enrolled in 2014 and those volunteers previously enrolled into the study over theage of 5 years old will be offered re-enrollment into the study.

Conditions
Malaria
Keywords
Mosquito, Membrane, Feeding, Parasites, Infection, Malaria
Medical subject headings
Malaria, Infections

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. a) Mosquito infectivity by DF, DMFA (a, b, and c), and SMFA (d and e), as measured by infection rate (number of infected vs. un- nfected mosquitoes), and oocyst counts in infected mosquitoes, both determined using microscopy.

    Measured: 24 months

  2. b) The period prevalence and density of gametocytes throughout the study period, as detected by thick smear and nucleic acid based techniques

    Measured: 24 months

Secondary outcomes (4)
  1. a)Antibody levels to sexual P. falciparum antigens, and other antigens of interest.

    Measured: 24 months

  2. b)Mosquito infectivity as measured by circumsporozoite protein (CSP) ELISA.

    Measured: 24 months

  3. c)Hemoglobin level as measured by HemoCue.

    Measured: 24 months

  4. d)Hemoglobin variants (hemoglobin S, C, alpha thalassemia), G6PD status, blood group/Rh.

    Measured: 24 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted25 May 2011 (estimated)
  2. Study start20 May 2011
  3. Study completion16 Nov 2017

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Prospective
Enrolment
816 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01360112
Sponsor's protocol ID
999911143
Other IDs
11-I-N143
Status last verified
16 Nov 2017
First submitted
20 May 2011
Last updated
7 Nov 2019
Results posted
No

Publications

  • Cheru L, Wu Y, Diouf A, Moretz SE, Muratova OV, Song G, Fay MP, Miller LH, Long CA, Miura K. The IC(50) of anti-Pfs25 antibody in membrane-feeding assay varies among species. Vaccine. 2010 Jun 17;28(27):4423-9. doi: 10.1016/j.vaccine.2010.04.036. Epub 2010 Apr 29.

    PubMed 20434549
  • Birkett AJ. PATH Malaria Vaccine Initiative (MVI): perspectives on the status of malaria vaccine development. Hum Vaccin. 2010 Jan;6(1):139-45. doi: 10.4161/hv.6.1.10462. Epub 2010 Jan 29. No abstract available.

    PubMed 20009524
  • Diallo M, Toure AM, Traore SF, Niare O, Kassambara L, Konare A, Coulibaly M, Bagayogo M, Beier JC, Sakai RK, Toure YT, Doumbo OK. Evaluation and optimization of membrane feeding compared to direct feeding as an assay for infectivity. Malar J. 2008 Dec 2;7:248. doi: 10.1186/1475-2875-7-248.

    PubMed 19055715

Questions about this trial

What is this clinical trial studying?

An observational study of Malaria, run by National Institute of Allergy and Infectious Diseases (NIAID) at 1 site in Mali.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 8 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 7 Nov 2019. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Mali. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

a) Mosquito infectivity by DF, DMFA (a, b, and c), and SMFA (d and e), as measured by infection rate (number of infected vs. un- nfected mosquitoes), and oocyst counts in infected mosquitoes, both determined using microscopy. (time frame: 24 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT01360112, which also lists 3 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Nov 2019.

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