Chemoprophylaxis and Plasmodium falciparum NF54 sporozoite immunization challenged by heterologous infectio

Recruitment & Eligibility

Status: Completed

Sex: Not specified

Target Recruitment: 40

Inclusion Criteria

- Subject is aged >= 18 and <= 35 years and in good health.
- Subject has adequate understanding of the procedures of the study and agrees to abide strictly thereby.
- Subject is able to communicate well with the investigator, is available to attend all study visits, lives in proximity to the trial centre (<10 km) or (if >10km) is willing to stay in a hotel close to the trial centre during part of the study (day 5 post-infection until three days post-treatment). Furthermore the subject will remain within the Netherlands during the challenge period, not travel to a malaria-endemic area during the study period, and is reachable (24/7) by mobile telephone throughout the entire study period.
- Subject agrees to inform his/her general practitioner about participation in the study and to sign a request to release by the GP any relevant medical information concerning possible contra-indications for participation in the study.
- Subject agrees to refrain from blood donation to Sanquin or for other purposes throughout the study period and for a defined period thereafter according to current Sanquin guidelines.
- For female subjects: subject agrees to use adequate contraception and not to breastfeed for the duration of study.
- Subject has signed informed consent.
- Subject agrees to refrain from intensive physical exercise (disproportionate to the subjects usual daily activity or exercise routine) for ten days following each immunization and during the malaria challenge period.

Exclusion Criteria

- Any history, or evidence at screening, of clinically significant symptoms, physical signs or abnormal laboratory values suggestive of systemic conditions, or psychiatric disorders, which could compromise the health of the volunteer during the study or interfere with the interpretation of the study results.
- Body weight <50 kg or Body Mass Index (BMI) <18.0 or >30.0 kg/m2 at screening.
- A heightened risk of cardiovascular disease, as determined by: an estimated ten year risk of fatal cardiovascular disease of >=5% at screening, as determined by the Systematic Coronary Risk Evaluation (SCORE); history, or evidence at screening, of clinically significant arrhythmia*s, prolonged QT-interval or other clinically relevant ECG abnormalities; or a positive family history of cardiac events in 1st or 2nd degree relatives <50 years old.
- A history of functional asplenia, sickle cell trait/disease, thalassaemia trait/disease or G6PD deficiency.
- History of epilepsy in the period of five years prior to study onset, even if no longer on medication.
- Positive HIV, HBV or HCV screening tests.
- Chronic use of i) immunosuppressive drugs, ii) antibiotics, iii) or other immune modifying drugs within three months prior to study onset (inhaled and topical corticosteroids and oral anti-histamines exempted) or expected use of such during the study period.
- History of malignancy of any organ system (other than localized basal cell carcinoma of the skin), treated or untreated, within the past 5 years.
- Any history of treatment for severe psychiatric disease by a psychiatrist in the past year.
- History of drug or alcohol abuse interfering with normal social function in the period of one year prior to study onset, or positive urine toxicology test for cocaine or amphetamines at screening or prior to infection or positive urine toxicology test for cannabis at inclusion or prior to infection.
- For female subjects: positive urine pregnancy test at screening or prior to infection.
- Any history of malaria, positive serology for P. falciparum, or previous participation in any malaria (vaccine) study.
- Known hypersensitivity to or contra-indications (including co-medication) for use of chloroquine, Malarone or artemether-lumefantrine, or history of severe (allergic) reactions to mosquito bites.
- Receipt of any vaccinations in the 3 months prior to the start of the study or plans to receive any other vaccinations during the study period or up to 8 weeks thereafter.
- Participation in any other clinical study in the 30 days prior to the start of the study or during the study period.
- Being an employee or student of the department of Medical Microbiology of the Radboudumc or the department of Internal Medicine.
- Any other condition or situation that would, in the opinion of the investigator, place the subject at an unacceptable risk of injury or render the subject unable to meet the requirements of the protocol.

Study & Design

Study Type: Interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>Time to parasitemia in volunteers after malaria challenge infection.</p><br>

Secondary Outcome Measures

Name	Time	Method
<p>• Antigen specificity of CPS-immunization induced antibodies for protection<br /><br>against pre-erythrocytic stages of Plasmodium falciparum.<br /><br>• The specificity of CPS-immunization induced T cell responses against<br /><br>pre-erythrocytic stages of Plasmodium falciparum.</p><br>

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