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Re-exposure of EHMI-8 Human Volunteers to Live Malaria Sporozoites

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00757887
Recruitment Status : Completed
First Posted : September 23, 2008
Last Update Posted : November 9, 2010
Information provided by:
Radboud University

Brief Summary:
In the EHMI-8 study (CMO 2006/207) the investigators induced sterile protection against P. falciparum challenge in healthy Dutch volunteers by repeated exposure to infected mosquitoes whilst under chloroquine prophylaxis. The surprisingly efficient induction of protection in this study strongly supports the development of whole parasite vaccines and is therefore an important finding to malaria vaccine development. In this study (EHMI8B) the investigators would like to explore the longevity of the protective immune response and simultaneously further characterise immune mechanisms responsible for protection by re-exposing EHMI-8 volunteers to infected mosquito bites.

Condition or disease Intervention/treatment Phase
P. Falciparum Malaria Biological: Exposure to 5 P. falciparum infected mosquitoes Not Applicable

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 15 participants
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Re-exposure of EHMI-8 Human Volunteers to Live Malaria Sporozoites
Study Start Date : October 2009
Actual Primary Completion Date : August 2010
Actual Study Completion Date : August 2010

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: EHMI8
Previously protected volunteers, N=10
Biological: Exposure to 5 P. falciparum infected mosquitoes
Five Anopheles Stephensi mosquitoes are infected with NF54 P.falciparum. volunteers are exposed to bites for 10 minutes.

Active Comparator: control
5 malaria-naive volunteers
Biological: Exposure to 5 P. falciparum infected mosquitoes
Five Anopheles Stephensi mosquitoes are infected with NF54 P.falciparum. volunteers are exposed to bites for 10 minutes.

Primary Outcome Measures :
  1. A significant difference in time of thick smear positivity between EHMI-8 and control volunteers [ Time Frame: 21 days ]
  2. A significant quantitative difference in parasitemia as measured by PCR between EHMI-8 and control volunteers [ Time Frame: 21 days ]
  3. A significant difference in kinetics of parasitemia between EHMI-8 and control volunteers as measured by PCR. [ Time Frame: 21 days ]
  4. A difference in occurrence of signs or symptoms between EHMI-8 and control volunteers [ Time Frame: 21 days ]

Secondary Outcome Measures :
  1. Difference in immunological parameters between EHMI-8 and control volunteers. [ Time Frame: 140 days ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 35 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion criteria

  1. Age > 18 and < 35 years healthy volunteers (males or females).
  2. General good health based on history and clinical examination.
  3. Negative pregnancy test.
  4. Use of adequate contraception for females
  5. All volunteers have to sign the informed consent form following proper understanding of the meaning and procedures of the study
  6. Volunteer agrees to inform the general practitioner and agrees to sign a request for medical information concerning contra-indications for participation in the study
  7. Willingness to undergo a P. falciparum sporozoite challenge
  8. Resident near the RUNMC, Nijmegen or agree to stay in a hotel room during the intensive period of the study (Day 5 till Day T +3)
  9. Reachable by mobile phone during the whole study period
  10. Availability to attend all study visits
  11. Agreement to refrain from blood donation to Sanquin or for other purposes, during the course of the study
  12. Willingness to undergo an HIV, hepatitis B and C test
  13. Negative urine toxicology screening test at screening visit and day before challenge

Exclusion criteria

  1. History of malaria other than participation in EHMI-8, or residence in malaria endemic areas within the past six months
  2. Plans to travel to endemic malaria areas during the study period.
  3. Only for newly recruited control volunteers: previous participation in any malaria vaccine study and/or positive serology for P. falciparum
  4. 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.
  5. History of diabetes mellitus or cancer (except basal cell carcinoma of the skin)
  6. History of arrhythmia's or prolonged QT-interval
  7. Positive family history in 1st and 2nd degree relatives of cardiac disease < 50 years old
  8. An estimated, ten year risk of fatal cardiovascular disease of ≥5%, as estimated by the Systematic Coronary Risk Evaluation (SCORE) system.
  9. Any clinically significant deviation from the normal range in biochemistry or haematology blood tests or in urine analysis
  10. Positive HIV, HBV or HCV tests
  11. Participation in any other clinical study within 30 days prior to the onset of the study
  12. Volunteers enrolled in any other clinical study during the study period
  13. Pregnant or lactating women
  14. Volunteers unable to give written informed consent
  15. Volunteers unable to be closely followed for social, geographic or psychological reasons
  16. Previous history of drug or alcohol abuse interfering with normal social function during a period of one year prior to enrolment in the study
  17. A history of psychiatric disease
  18. Known hypersensitivity for anti-malaria drugs
  19. History of severe reactions or allergy to mosquito bites
  20. The use of chronic immunosuppressive drugs, antibiotics, or other immune modifying drugs within three months before study onset (inhaled and topical corticosteroids are allowed) and during the study period
  21. Contra-indications to Malarone® including treatment taken by the volunteers that interfere with Malarone®
  22. Any confirmed or suspected immunosuppressive or immunodeficiency condition, including asplenia
  23. Co-workers of the departments of Medical Microbiology or Internal Medicine of the Radboud University Nijmegen Medical Centre

Information from the National Library of Medicine

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 identifier (NCT number): NCT00757887

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UMC St. Radboud
Nijmegen, Netherlands, 6500 HB
Sponsors and Collaborators
Radboud University
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Principal Investigator: Robert Sauerwein, Prof. Dr. Radboud University

Additional Information:
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Prof. Dr. R.W. Sauerwein, Radboud University Identifier: NCT00757887     History of Changes
Other Study ID Numbers: EHMI-8B
First Posted: September 23, 2008    Key Record Dates
Last Update Posted: November 9, 2010
Last Verified: October 2009
Keywords provided by Radboud University:
experimental infection
Additional relevant MeSH terms:
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Malaria, Falciparum
Protozoan Infections
Parasitic Diseases