Evaluation of Reproducibility of a Sporozoite Challenge Model for Plasmodium Vivax in Human Volunteers
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| ClinicalTrials.gov Identifier: NCT00367380 |
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Recruitment Status :
Completed
First Posted : August 22, 2006
Results First Posted : June 3, 2014
Last Update Posted : March 22, 2021
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The study is a randomized open label clinical trial to verify the reproducibility of a sporozoite challenge model for Plasmodium vivax in humans. The verification of the reproducibility of such a model will make it possible to evaluate the efficacy of candidate P. vivax vaccines in Phase 2a trials. The study is divided into two successive steps:
Step A Parasite Blood Donation: Volunteers will be recruited passively from a group of patients who present with active P. vivax infection and accept to donate infected blood. Samples of P. vivax infected blood will be collected and will be screened for infectious diseases, according to standard blood bank procedures. Colonized Anopheles albimanus mosquitoes will be fed with this blood using a Membrane Feeding Assay (MFA). Sixteen (16) days after, selected positive mosquito batches will be used for step B.
Step B Challenge: After informed consent signature, a total of 18 healthy volunteers will be randomly allocated to Groups 1, 2 and 3, of 6 volunteers each and will be challenged with the bite of 3±1, P. vivax infected mosquitoes. Each group will be exposed to a different isolated parasite. Volunteers will be closely monitored post infection, and will be treated as soon as blood infection becomes patent as ascertained by microscopic examination of thick blood smears (TBS). Comparison of data obtained in the three different groups will be used to determine reproducibility of challenge model.
Primary objective: To demonstrate that naïve human volunteers can be safely and reproducibly infected by the bite of An. albimanus mosquitoes carrying P. vivax sporozoites in their salivary glands.
Secondary objective: To determine the influence of the type of parasite isolated on reproducibility and safety of the challenge model with P. vivax in human volunteers
Hypothesis:It is possible to safely develop a reproducible P. vivax infection in human volunteers using P. vivax experimentally infected An. albimanus mosquitoes.
| Condition or disease | Intervention/treatment | Phase |
|---|---|---|
| MALARIA FEVER Sweating Fever Chills ANEMIA | Other: 413ABM Other: 414WRR Other: 418JAL | Phase 2 |
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| Study Type : | Interventional (Clinical Trial) |
| Actual Enrollment : | 18 participants |
| Allocation: | Randomized |
| Intervention Model: | Parallel Assignment |
| Masking: | None (Open Label) |
| Primary Purpose: | Basic Science |
| Official Title: | Evaluation of Reproducibility of a Sporozoite Challenge Model for Plasmodium Vivax in Human Volunteers |
| Study Start Date : | December 2006 |
| Actual Primary Completion Date : | December 2006 |
| Actual Study Completion Date : | March 2007 |
| Arm | Intervention/treatment |
|---|---|
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Experimental: Group 1
6 volunteers to be challenged with the infected with +/-3 mosquito bites from batch 413ABM
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Other: 413ABM
+/- 3 bites of Anopheles albimanus mosquitoes infected through membrane feeding with blood of the P. vivax infected volunteers 413ABM |
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Experimental: Group 2
6 volunteers to be challenged with the infected with +/-3 mosquito bites from batch 414WRR
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Other: 414WRR
+/- 3 bites of Anopheles albimanus mosquitoes infected through membrane feeding with blood of the P. vivax infected volunteers 414WRR |
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Experimental: Group 3
6 volunteers to be challenged with the infected with +/-3 mosquito bites from batch 418JAL
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Other: 418JAL
+/- 3 bites of Anopheles albimanus mosquitoes infected through membrane feeding with blood of the P. vivax infected volunteers 418JAL |
- Infection for P. Vivax [ Time Frame: Twenty eight days ]Thick blood smear was performed to patients daily on days 7 to 23, and every other day until day 29. Any prove of P. vivax infection was considered positive and confirmed later by real time polymerase chain reaction (rPCR).
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
| Ages Eligible for Study: | 18 Years to 45 Years (Adult) |
| Sexes Eligible for Study: | All |
| Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
- Healthy, adult male or non-pregnant females (18-45 years of age).
- Capacity to sign a free informed consent form of participation along with two witnesses.
- Use of adequate contraceptive method from the initiation of the study until three months after sporozoite challenge.
- No plans to travel to malaria endemic areas during the course of the study (a year).
- No plans to travel outside the study area from the 7th day until 31st day after the challenge.
- Reachable by phone during the whole study period.
- Able to participate during the whole study period.
Exclusion Criteria:
- Are less than 18 and over 45 years of age.
- Are female who is pregnant at serum positive B-HCG screening, planning to become pregnant or who is nursing.
- Have a Duffy negative phenotype.
- Have a G-6-PD deficiency or any other hemoglobinopathy.
- Current or past infection with any species of malaria as demonstrated by a positive TBS on screening or history of a documented positive blood smear. P. vivax IFAT of 1
- Have a known history of allergy to antimalarial drugs or immediate type hypersensitivity reactions to mosquito bites.
- Clinical or laboratory evidence of significant systemic disease, including hepatic, renal, cardiac, immunologic or hematological disease, HIV positive or have any other known immunodeficiency (including receiving immunosuppressive therapy or a history of splenectomy); infected with hepatitis B or C virus; have a history of autoimmune disease (including inflammatory bowel disease, hemolytic anemia, autoimmune hepatitis, rheumatoid arthritis, lupus, etc.) or connective tissue disease or have any other serious underlying medical condition.
- Clinically significant laboratory abnormalities as determined by the Investigator(s).
- Plan to have surgery between enrollment and the end of the challenge follow-up.
- Previous history of alcoholism or drugs use which interfere with social activities of the volunteer
- Have any other conditions that are determined by at least two concurring investigators that may interfere with the capacity to provide free and willing informed consent.
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00367380
| Colombia | |
| Malaria Vaccine and Drug Development Center | |
| Cali, Valle, Colombia, 25574 | |
| Principal Investigator: | Socrates Herrera, MD | Director |
Publications:
| Responsible Party: | Malaria Vaccine and Drug Development Center |
| ClinicalTrials.gov Identifier: | NCT00367380 |
| Other Study ID Numbers: |
MVDC-2006-004 |
| First Posted: | August 22, 2006 Key Record Dates |
| Results First Posted: | June 3, 2014 |
| Last Update Posted: | March 22, 2021 |
| Last Verified: | February 2021 |
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Malaria Sporozoite Challenge Model Plasmodium vivax Human Volunteers |
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Malaria Fever Protozoan Infections Parasitic Diseases |
Infections Vector Borne Diseases Body Temperature Changes |

