Study to Investigate the Induction of an Protective Immune Response to Malaria

This study has been completed.
Sponsor:
Information provided by:
Radboud University
ClinicalTrials.gov Identifier:
NCT00442377
First received: February 28, 2007
Last updated: August 15, 2007
Last verified: August 2007
  Purpose

The objective of the study is to induce a protective immune response against malaria in healthy human volunteers. The different parts of the immune response will then be studied.


Condition Intervention
Falciparum Malaria
Procedure: exposure to malaria sporozoites

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double-Blind
Primary Purpose: Prevention
Official Title: Exposure of Human Volunteers to Live Malaria Sporozoites Under Chloroquine Prophylaxis

Resource links provided by NLM:


Further study details as provided by Radboud University:

Primary Outcome Measures:
  • A significant difference in time of thick smear positivity between exposed and control groups
  • A significant difference in parasitemia as measured by 18S Pf NASBA between exposed and control group
  • A significant difference in kinetics of parasitemia between exposed and control groups as measured by 18S Pf NASBA.
  • A difference in occurrence or height of fever between exposed and control groups.

Secondary Outcome Measures:
  • Significant differences in immune response between exposed and control volunteers (including NK-cell reactivity, TLR reactivity and regulatory T-cell reactivity)
  • Significant differences in the outcome of in vitro functional malaria assays between exposed and control volunteers
  • Significant differences in cellular reactivity against Pf antigens
  • Significant differences in parasite VAR gene expression during infection
  • The identification of immune mechanisms that correlate with protection
  • 6. The identification of potential vaccine candidates that correlate with protection

Estimated Enrollment: 15
Study Start Date: January 2007
Study Completion Date: July 2007
Detailed Description:

Efforts to develop vaccines against malaria still represent a substantial focus of current research activities. Factors that have hampered the development of a subunit vaccine include the complexity of the malaria life cycle, the wide variety of immune response induced by the malaria parasite, and an incomplete knowledge of protective immunity. This study is therefore aimed at inducing protective immunity against malaria in 15 healthy volunteers. Volunteers will be exposed to the bites of infectious mosquitoes 3 times with live P. falciparum sporozoites under chloroquine prophylaxis. Challenge with infected mosquitoes will be given after stopping chloroquine prophylaxis.

Five volunteers will form a control group; they will be exposed to non-infectious mosquitoes under chloroquine prophylaxis.

Endpoints include the time and height of parasitemia after challenge, the development of fever and immunological parameters.

  Eligibility

Ages Eligible for Study:   18 Years to 45 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Age > 18 and < 45 years healthy volunteers (males or females).
  • General good health based on history and clinical examination.
  • All volunteers have to sign the informed consent form.
  • Negative pregnancy test.
  • Use of adequate contraception for females
  • Reachable by phone during the whole study period.
  • Volunteer agrees to inform the general practitioner and agrees to sign a request for medical information concerning contra-indications for participation in the trial

Exclusion Criteria:

  • History of malaria or residence in malaria endemic areas within the past six months.
  • Positive serology for P. falciparum
  • Previously participated in any malaria vaccine study
  • Symptoms, physical signs and laboratory values suggestive of systemic disorders, including renal, hepatic, cardiovascular, pulmonary, skin, immunodeficiency, psychiatric and other conditions, which could interfere with the interpretation of the study results or compromise the health of the volunteers.
  • Cardiovascular risk >10% according to European guidelines, taking into account sex, age, cholesterol, weight, smoking habits, blood pressure, diabetes
  • Any laboratory abnormalities on screened blood samples beyond the normal range, as defined at UMC St Radboud. Positive HIV, HBV or HCV tests.
  • Volunteers should not be enrolled in any other clinical trial during the whole trial period.
  • Volunteers should not receive chronic medication, especially immunosuppressive agents (steroids, immunomodulating or immunosuppressive drugs) during the three months preceding the screening visit or during the study period.
  • Pregnant or lactating women.
  • Volunteers unable to give written informed consent.
  • Volunteers unable to be closely followed for social, geographic or psychological reasons.
  • Previous history of drug or alcohol abuse interfering with normal social function during a period of one year prior to enrolment in the study.
  • Known hypersensitivity for anti-malaria drugs
  • Volunteers are not allowed to travel to malaria endemic countries during the study period.
  Contacts and Locations
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, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00442377

Locations
Netherlands
Radboud University Nijmegen Medical Centre
Nijmegen, Netherlands, 6500 HB
Sponsors and Collaborators
Radboud University
Investigators
Principal Investigator: Robert Sauerwein, Prof Radboud University
  More Information

Additional Information:
No publications provided by Radboud University

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
ClinicalTrials.gov Identifier: NCT00442377     History of Changes
Other Study ID Numbers: EHMI-8
Study First Received: February 28, 2007
Last Updated: August 15, 2007
Health Authority: Netherlands: Medical Ethics Review Committee (METC)

Keywords provided by Radboud University:
Falciparum
Plasmodium
Malaria

Additional relevant MeSH terms:
Malaria
Malaria, Falciparum
Protozoan Infections
Parasitic Diseases

ClinicalTrials.gov processed this record on July 31, 2014