NCT01082341

Immunization of Human Volunteers With P. Vivax Irradiated Sporozoites

Phase 1 and Phase 2a Clinical Trial:Immunization of Human Volunteers With P. Vivax Irradiated Sporozoites

• Status: Completed
• Phase: Phase 1 / Phase 2
• Study type: Interventional
• Enrollment: 27 (actual)
• Sponsor: Malaria Vaccine and Drug Development Center · Academic / Other
• Sex: All
• Age: 18 Years – 45 Years
• Healthy volunteers: Accepted

Summary

It is possible to safely protect human volunteers immunized with P. vivax irradiated sporozoites from P. vivax challenge with live sporozoites.

Detailed description

Title: Phase 1 and Phase 2a Clinical Trial: Immunization of human volunteers with P. vivax irr-spz. (Short name: Irrad-SPZ) Population 27 healthy adult volunteers, males and non-pregnant females, between 18-45 years of age, who fulfill inclusion/exclusion criteria (described below) as determined by clinical history and serological tests. Approximately 20 parasitized blood-donor volunteers will be required to infected Anopheles mosquitoes which will be used to immunize volunteers with a total of 1000-1500 infected mosquitoes, during 8-10 months. Afterwards challenge to prove protection. Number of Sites: 2 Study Duration: 2 years. Subject Duration : Step1: 1-2 hours to blood donors; Step 2 and 3: 2 years to immunized volunteers Objectives Primary • To assess the safety and protective efficacy of P. vivax irradiated sporozoite vaccination. Secondary * To determine the immune responses and duration elicited by the P. vivax challenge in human Fy(+) volunteers previously immunized with irr-spz, as compared with non-immunized human volunteers. * To determine the immune responses and duration elicited by irr-spz immunization scheme in human Fy(+) volunteers; comparing it with the same immunization scheme with non irr-spz in Fy(-) participants, and also with controls exposed to the same mosquito bite scheme as that of immunization but using mosquitoes without parasite infection. * To study new antigens potentially useful to induce pre-erythrocytic protection against P. vivax malaria infection

Conditions

• Malaria

Interventions

Type	Name	Description
BIOLOGICAL	Immunization with P. vivax irradiated sporozoites	Anopheles albimanus mosquitoes will be infected by artificial membrane feeding using blood from P. vivax infected donors. Once mosquitoes are positive will be irradiated at 15000 cGy and kept in boxes until use. 14 Fy(+) human volunteers in the experimental group will be immunized with 1,000-2,000 P. vivax irrad-spz bites. Seven Fy(+) volunteers in the control group will be exposed to non-infected mosquito bites. Six Fy(-) volunteers will be exposed to infective mosquito bites. For the challenge both the immunized and control groups will be exposed to 3 ± 1 infective mosquito bites. Volunteers will be closely monitored post infection and will be treated with antimalarials.

Timeline

• Start date: 2012-06-01
• Primary completion: 2015-05-01
• Completion: 2017-09-01
• First posted: 2010-03-08
• Last updated: 2018-03-23

Locations

1 site across 1 country: Colombia