Active clinical trials for "Malaria"

Primaquine (PQ) is the only widely available treatment to prevent P. vivax relapses. World Health Organization recommends increased PQ doses in East Asia and Oceania, frequently relapsing strains. In 2005, the Centers for Diseases Control and Prevention began also recommending higher dose PQ to treat infections from all parts of the world. In Latin America, PQ for a radical cure has been largely implemented as 3.5 mg/kg over 14 days (standard dose, long-course, PQsd14) or 3.5 mg/kg over 7 days (short-course, or PQsd7) in combination with chloroquine (CQ). A recent randomized controlled trial in Brazil showed that a 7 mg/kg double dose regimen over 14 days (PQdd14) was superior in preventing relapses compared to the standard of care regimen in Brazil of 3.5 mg/kg over 7 PQsd7 Direct Observed Therapy (DOT) and PQsd7 without DOT and with or 14 days PQsd14 with DOT (92% versus 66% were relapse-free in the 6-month follow-up in adjusted analyses). These data were presented at the 2019 PAHO Malaria Technical Advisory Group (TAG) meeting. To inform whether there should be a policy change by Panamerican Health Organization, the Malaria TAG recommended more evidence from the results of another trial to confirm the efficacy of high versus low-dose PQ. This project aims to generate the necessary evidence to inform a policy decision regarding high-dose PQ. Impact Malaria (IM) proposes to conduct another trial, per the PAHO Malaria TAG's recommendation, assessing the efficacy of high-dose PQ compared to low-dose PQ. The objective is to compare a standard regimen, which in Colombia is PQsd14 (3,5mg/kg divided in 14 days), to a double dose alternative PQ 7 mg/kg double dose regimen over 14 days (PQdd14).

The purpose of this study is to assess the safety and efficacy of adjuvanted R21 alone and in combination with a viral-vectored vaccine regimen (constituting adjuvanted R21 + ChAd63 and MVA encoding ME-TRAP) against malaria sporozoite challenge in healthy malaria-naive volunteers. Healthy adult volunteers will be recruited in London, Oxford and Southampton. All vaccinations will be administered intramuscularly. The study involves having either two, three or five vaccinations and then undergoing challenge infection with malaria, or receiving no vaccinations then undergoing challenge infection with malaria.

This study is designed to evaluate efficacy, immunogenicity and safety of various dose schedules of GSK Biologicals' candidate malaria vaccines RTS,S/AS01B (adult formulation) and RTS,S/AS01E (pediatric formulation) in healthy malaria-naïve subjects aged 18-55 years. The purpose of this study is to investigate whether changes in dosing schedule are associated with increased or equivalent protection, and to evaluate the immune mechanisms associated with vaccine efficacy under varying dosing schedules.

This is a first-in-human, randomized clinical trial of PfSPZ-GA1 Vaccine (genetically attenuated PfSPZ) in healthy malaria-naïve adult volunteers. This Phase 1 trial is divided into two stages, Stage A and B. Stage A is an open label, single center, dose escalation study in 19 volunteers. Stage B is a multi-center, double blind, randomized, placebo-controlled trial in 48 volunteers. The primary objective of this study is to determine the safety and tolerability of direct venous inoculation (DVI) of PfSPZ-GA1 Vaccine in healthy adults.

This Phase 1 trial will include 16 subjects who will receive the Genetically-attenuated p52-/p36-/sap1- Plasmodium falciparum Parasites (GAP3KO) vaccine administered by the bite of approximately 200 infected Anopheles stephensi Mosquitoes in a controlled clinical environment and 12 Controlled Human Malaria Infection (CHMI) infectivity controls (six for each of the two CHMIs). Subjects will be observed for adverse events after each GAP3KO administration. Solicited local and systemic Adverse Events (AEs) will be recorded on a memory aid beginning of the day of first vaccine administration and continuing through 28 days after the last administration. During the vaccination phase clinical laboratory evaluations for safety will be performed on venous blood. Unsolicited AEs will be collected from the day of first vaccination through 28 days after last vaccination and serious adverse events (SAEs) will be collected from the day of first GAP3KO administration through the end of study follow-up. Subjects will be monitored for possible breakthrough peripheral parasitemia with qRT-PCR testing. Four weeks after the last GAP3KO administration, all subjects who completed the immunization phase (up to 16) and a group of six malaria-naïve infectivity controls will be challenged on the same day with wild-type Plasmodium falciparum NF54 sporozoites. Approximately twenty-six weeks after that challenge, all of the protected subjects in Arms 1 and 2 (up to 16) and another six malaria-naïve infectivity controls will receive five infectious A. stephensi mosquito bites on the same day using standard CHMI procedures. For subjects in Study Arms 1 and 2 without documented parasitemia additional post-CHMI follow-ups will occur. For subjects in Study Arms 1 and 2 with documented parasitemia after the first CHMI or who are discontinued for other reasons after the first CHMI, and for the infectivity controls, additional follow ups will occur. Serious Adverse Events (SAEs) will be recorded from the day of CHMI through the end of study follow up and clinical laboratory evaluations for safety will be performed on Day 29 and as clinically indicated (all subjects) and, for subjects with documented parasitemia, on the day malaria treatment is initiated and three days after malaria treatment is initiated. The primary objectives are: 1) To assess the safety and reactogenicity of candidate GAP3KO malaria vaccine when administered by the bite of approximately 200 infected mosquitoes on a five dose schedule, with the first four vaccinations given four weeks apart and the fifth vaccination given eight weeks after the fourth vaccination, and on a three dose schedule, with the second vaccination given four weeks after the first vaccination and the third vaccination given eight weeks after the second vaccination, to healthy malaria-naïve adults aged 18 through 50 years , 2) To confirm attenuation of GAP3KO parasites by assessing the occurrence of breakthrough peripheral parasitemia from the time of first GAP3KO administration through 28 days after last GAP3KO administration.

This is a clinical trial in which healthy volunteers will be administered an experimental malaria vaccine, R21. The R21 vaccine will be administered with the adjuvant AS01B. All vaccinations will be administered intramuscularly. Each volunteer will receive three vaccinations in total. There are two different vaccine schedules: Group 1 will receive R21 10µg with AS01B on days 0, 28, and 56. Group 2 will receive R21 50µg with AS01B on days 0, 28, and 56. The study will assess the safety of the vaccine, and the immune responses to the vaccination. Immune responses are measured by tests on blood samples. Healthy adult volunteers will be recruited in Oxford and Southampton, England.

This study is a phase 1, randomized, double-blind, placebo-controlled, dose escalation trial of Sanaria's irradiated sporozoite vaccine (PfSPZ vaccine). The primary objective of this protocol is to determine the safety and reactogenicity of the PfSPZ Vaccine in malaria-experienced healthy adults. The study duration shall be 34 months and subject participation duration shall be 15-26 months.

This is a single center, randomized, placebo-controlled, double-blind trial to assess the safety and immunogenicity of PfSPZ Vaccine administered by direct venous inoculation (DVI). The study to be conducted in Baney District, Bioko Island, Equatorial Guinea (EG), will be to establish whether three doses of the higher regimen - three doses of 2.7x10^5 PfSPZ of the PfSPZ Vaccine administered at 8 week intervals - is as well-tolerated and efficacious in malaria exposed African adults as the five dose regimens. Specifically, the trial will address the following objectives: is the three dose regimen: Safe and well tolerated in Equatoguinean (EG) adults. As immunogenic in EG adults as is the five-dose regimen of 1.35x10^5 PfSPZ in Tanzanian and U.S. adults or as three-, four- and five-dose regimens of 2.7x10^5 PfSPZ being tested in Tanzanian, Malian and U.S. adults. In addition, as an exploratory objective, the volunteers in the EG trial will be followed longitudinally to measure the incidence of malaria during the initial six months following immunization, providing a preliminary assessment of efficacy.

The purpose of this study is to demonstrate that volunteers can be safely and reproducibly infected with Plasmodium vivax (P. vivax) by the bites of experimentally infected Anopheles dirus (An. dirus) mosquitoes carrying P. vivax sporozoites in their salivary glands.

The purpose of this study is to determine safety and efficacy of prenatal iron supplementation in an area of high malaria burden among women who are not anemic or iron deficient.