Phase I and IIa trial for assessment of safety, immunogenicity and efficacy against sporozoite challenge of the candidate malaria vaccine PfLSA-3-rec.

Recruitment & Eligibility

Status: Completed

Sex: Not specified

Target Recruitment: 36

Inclusion Criteria

-Male and female age >=18 and <= 45 years
-Good general health based on history, physical en laboratory examination
-Available for and willingness to undergo a P. falciparum sporozoite challenge following the immunization course
-Resident near the Radboud University Medical Center Nijmegen, having 24h access to a telephone
-Living with a third party that could contact the clinicians in case of alteration of conscience
-Agreement to refrain from blood donation during the course of the study and afterwards
-Negative pregnancy test and the use of effective contraception during the whole study period

Exclusion Criteria

-Any history of malaria
-Known exposure to malaria in the previous 6 months, defined as a visit to a malaria-endemic region. For practical purposes, all regions for which malaria chemoprophylaxis is advised by The Dutch National Coordination Centre for Travellers Health (LCR) are considered malaria-endemic
-Planned to travel to endemic malaria areas during the study period
-Prior administration of an investigational malaria vaccine
-Administration of a vaccine or gammaglobulin not foreseen by the clinical trial protocol within 30 days prior to the first immunisation and up to six months after the last immunisation.
-Participation in any other clinical trial within 90 days prior to the onset of the trial or more than four clinical trials in the past year
-The use of chronic immunosuppressive drugs or other immune modifying drugs within three months of vaccination (inhaled and topical corticosteroids are allowed)
-Positive serological tests for P falciparum (LSA-3) ELISA and/or a positive P. falciparum PCR
-Known hypersensitivity to vaccine components
-Contra-indications to Riamet® including treatment taken by the volunteers that interfere with Riamet® (e.g. concurrent use of medicines that prolong QT-interval)
- 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
-An estimated, ten year risk of fatal cardiovascular disease of >=5%, as estimated by the Systematic Coronary Risk Evaluation (SCORE) system.

Study & Design

Study Type: Interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>Phase I: The proportion and severity of adverse events in both intervention<br /><br>groups.<br /><br>Phase IIa: The proportion of volunteers reaching day 21 post-infection without<br /><br>or with a delayed onset of parasitemiae compared to control group (parasitemiae<br /><br>defined as >=2 parasites per 200 fields in a thick blood film).</p><br>

Secondary Outcome Measures

Name	Time	Method
<p>Phase I and IIa: Immunogenicity evaluation: antibody and cellular responses to<br /><br>vaccination with PfLSA-3-rec vaccine formulations.<br /><br>Phase IIa: The length of time (in hours) between parasite inoculation and<br /><br>detection of parasitemia, if any, up to 21 days.</p><br>