Safety and Immunogenicity of the Malaria Vaccine, R21/MatrixM, in Healthy Thai Adults
Malaria,FalciparumMalaria remains one of the leading causes of morbidity and mortality worldwide. Plasmodium falciparum is a complex pathogen with numerous immune evasion mechanisms which has added layers of complexity to the development of safe and protective vaccines. There remains an urgent need to identify and develop more protective and more affordable vaccine candidates that could achieve the World Health Organization (WHO) goal of 75% efficacy against clinical malaria. R21 is a novel pre-erythrocytic candidate malaria vaccine. R21 includes Hepatitis B surface antigen (HBsAg) fused to the C-terminus and central repeats of the circumsporozoite protein of P. falciparum (CSP), which self-assemble into virus-like particles in yeast. R21 lacks the excess HBsAg found and comprises only fusion protein moieties. R21/MatrixM (MM) had a favourable safety profile and was well tolerated. The majority of adverse events were mild, with the most common event being fever. None of the serious adverse events were attributed to the vaccine. At one year, vaccine efficacy remained high, at 77%. Participants vaccinated with R21/MM showed high titres of malaria-specific anti- Asn-Ala-Asn-Pro (NANP) antibodies 28 days after the third vaccination, which were almost doubled with the higher adjuvant dose. Titres waned but were boosted to levels similar to peak titres after the primary series of vaccinations after a fourth dose administered one year later. Currently, there are no safety and immunogenicity data for the use of R21/MatrixM in Asian populations. This trial will generate the required data for the use of this vaccine in Asia. For integration with the current targeted malaria elimination (TME) activities, which provide mass drug administrations at months M0, M1, and M2, it would be most efficient and practical to provide the vaccine at the same intervals. In summary: The investigators propose to conduct a safety and immunogenicity trial of R21/MatrixM in Thai adults. The major aims of this study are to 1) assess the safety and immunogenicity of R21/MatrixM in Thai adults 2) confirm that the co-administration of antimalarial drugs with the malaria vaccine R21/MatrixM does not reduce the immunogenicity of the vaccine and 3) assess the absorption and pharmacokinetics of antimalarial drugs piperaquine, and a single low dose of primaquine (SLDPQ) when co-administered with R21/MatrixM. This is a randomized, open label, single centre, Phase 2 study. 120 healthy non-pregnant Thai adults, aged 18-55 years, inclusive, will be recruited. Each participant will be randomized into one of the following study arms in a ratio of 5:5:2, as follows: R21/MatrixM + Dihydroartimisinin (DHA)-Piperaquine (PIP)+ primaquine (PQ) (Group 1, n=50) will receive R21/MatrixM + 3 doses DHA-PIP+PQ at Month 0, Month 1 and Month 2 R21/MatrixM only (Group 2, n=50) will receive R21/MatrixM standard dose at Month 0, Month 1 and Month 2 DHA-PIP+PQ only (Group 3, n=20) will receive 3 doses DHA-PIP+PQ at Month 0, Month 1 and Month 2
Evaluating ATSBs for Malaria Reduction in Kenya
MalariaThe effectiveness of long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) in western Kenya are threatened by insecticide resistance and vector behaviour changes toward early evening and outdoor biting malaria vectors. New tools to control malaria are needed to reduce and even interrupt malaria transmission. Attractive Targeted Sugar Bait (ATSB) is a promising new intervention designed to attract and kill mosquitoes, including those that IRS and LLINs do not effectively target. The ATSB 'bait stations' are A4-sized panels containing thickened fruit syrup laced with a neonicotinoid insecticide, dinotefuran, to attract and kill the foraging vectors. Entomological field trials in western Mali showed that ATSBs successfully reduce mosquito densities and longevity and thus have the potential to reduce malaria transmission. In Kenya, the investigators will conduct an open-label cluster-randomized controlled trial in 80 village clusters (40 per arm) to evaluate the effect of ATSBs on the burden of malaria. During two years, households in half of these village clusters will receive two or three ATSB bait stations per household structure on exterior walls approximately 1.8 meters above the ground. ATSBs will be replaced every six months. The primary outcome will be the incidence of clinical malaria in children aged 1-<15 years enrolled in a prospective cohort followed monthly for about six months each during a 2-year period. Secondary outcomes include malaria infection prevalence assessed by rapid diagnostic tests through household surveys and the case burden of clinical malaria assessed by passive facility-based and community-based surveillance. The study includes entomological monitoring and nested acceptability, feasibility, and health economics studies. The stand-alone trial in western Kenya is a part of a multi-country ATSB consortium conducting similar trials in Zambia and Mali.
A Study to Assess the Experimental Malaria Vaccines RH5.2-VLP and R21
MalariaPlasmodium FalciparumThis is a Phase Ib multi-stage Plasmodium falciparum malaria vaccine study to assess the safety and immunogenicity of the blood-stage vaccine candidate RH5.2 virus-like particle (VLP) in Matrix-MTM and the pre-erythrocytic stage vaccine candidate R21 in Matrix-MTM, both alone and in combination, in adults and infants in the Gambia
Optimal Chemopreventive Regimens to Prevent Malaria and Improve Birth Outcomes in Uganda
MalariaThis trial tests the hypothesis that intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) + dihydroartemisin-piperaquine (DP) will significantly reduce the risk of adverse birth outcomes compared to IPTp with SP alone or DP alone. This double-blinded randomized controlled phase III trial of 2757 HIV uninfected pregnant women enrolled at 12-20 weeks gestation will be randomized in equal proportions to one of three IPTp treatment arms: 1) SP given every 4 weeks, or 2) DP given every 4 weeks, or 3) SP+DP given every 4 weeks. SP or DP placebos will be used to ensure adequate blinding is achieved in the study and follow-up will end 28 days after giving birth.
Adaptive Interventions for Optimizing Malaria Control: A Cluster-Randomized SMART Trial
LLINPBO LLIN2 moreIn the past decade, massive scale-up of long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) have led to significant reductions in malaria mortality and morbidity. Nonetheless, malaria burden remains high, and a dozen countries in Africa show a trend of increasing malaria incidence over the past several years. The high malaria burden in many areas of Africa underscores the need to improve the effectiveness of intervention tools by optimizing first-line intervention tools and integrating newly approved products into control programs. Vector control is an important component of the national malaria control strategy in Africa. Because transmission settings and vector ecologies vary among countries or among districts within a country, interventions that work in one setting may not work well in all settings. Malaria interventions should be adapted and re-adapted over time in response to evolving malaria risks and changing vector ecology and behavior. The central objective of this application is to design optimal adaptive combinations of vector control interventions to maximize reductions in malaria burden based on local malaria transmission risks, changing vector ecology, and available mix of interventions approved by the Ministry of Health in each target country. The central hypothesis is that an adaptive approach based on local malaria risk and changing vector ecology will lead to significant reductions in malaria incidence and transmission risk. The aim of this study is to use a cluster-randomized sequential, multiple assignment randomized trial (SMART) design to compare various vector control methods implemented by the Ministry of Health of Kenya in reducing malaria incidence and infection, and develop an optimal intervention strategy tailored toward to local epidemiological and vector conditions.
A Study to Assess the Safety and Effectiveness of Two Experimental Malaria Vaccines
MalariaMalaria,Falciparum3 moreMalaria is a major public health problem. There were around 240 million cases of malaria and 627,000 deaths worldwide in 2020. There is a great need for a safe, effective malaria vaccine and the team at University of Oxford is trying to make vaccine(s) which can prevent serious illness and death. This study is being done to assess an experimental malaria vaccine for its ability to prevent malaria illness. This is done using a 'blood-stage challenge model'. This is when volunteers are infected with malaria parasites using malaria-infected red blood cells. The vaccine we are testing in this part of the study is called "RH5.2-VLP". It is given with an adjuvant called "Matrix-M". This is a substance to improve the body's response to a vaccination. RH5.2-VLP is being tested for the first time in humans in this trial. The Matrix-M adjuvant has been given to tens of thousands of people, with no major concerns, such as illness. The aim is to use this vaccine and adjuvant to help the body make an immune response against parts of the malaria parasite. This study will assess: The safety of the vaccine in healthy participants. The response of the human immune system to the vaccine. The ability of the vaccine to prevent malaria illness (Group 2 only). We will do this by giving healthy adult participants (aged 18-45) three of the vaccines and/or expose participants to malaria infection at the Centre for Clinical Vaccinology and Tropical Medicine (CCVTM), Churchill Hospital in Oxford. We will then do blood tests and collect information about any symptoms that occur after vaccination. There will be 19 to 54 visits, lasting between 3 months to 2 years and 2 months.
A Trial For The Study of Falciparum Malaria Protein 013 Administered Via Intramuscular Injection...
Vaccine ReactionA Phase 1, open label clinical study to evaluate the safety, immunogenicity, tolerability and efficacy of Plasmodium falciparum Malaria Protein 013 (FMP013) combined with (ALF with QS-21), saponin molecule derived from the bark of Quillaja species (ALFQ)) in healthy adult volunteers at different doses and dosing schedules.
Chemoprevention Efficacy Study in Burkina Faso
MalariaThe aim of this study is to determine whether Seasonal Malaria Chemoprevention (SMC) remains effective in the health district of Nanoro in the Centre-Ouest region or Boussé in the Plateau Central region. It also aims to assess the protective efficacy of the antimalarial drugs used in SMC in the target population and to investigate levels of parasite resistance in the study districts. According to the results, this trial should provide the evidence needed to change the drugs used in SMC. A Type II hybrid effectiveness-implementation study design will be used to evaluate the effects of a clinical intervention on relevant outcomes whilst collecting information on implementation. It is designed to determine feasibility and effectiveness of an innovative intervention, as well as the protective efficacy of the antimalarial drugs used. The study consists of two components: 1) Conducting a prospective cohort study to determine the protective efficacy of the drug combination Sulfadoxine-Pyrimethamine and Amodiaquine (SPAQ) (if SPAQ provides 28 days of protection from infection) and whether drug concentrations and/or resistance influence the duration of protection; 2) Conducting a resistance markers study in symptomatic patients in the research district.
Evaluation of the STANDARD G6PD Rapid Test for Assaying the Enzymatic Activity of G6PD in French...
PaludismIn French Guiana, malaria is endemic and two species predominate: P. falciparum and P. vivax. The treatments against Plasmodium vivax malaria are: nivaquine for 3 days against circulating blood parasites and primaquine for 14 days against parasites dormant in the liver. Primaquine can cause iatrogenic hemolytic anemias in patients with favism, i.e. G6PD deficiency. This anemia can be severe enough to cause the death of the deficient patient. Thus, the WHO and HCSP recommendations indicate that a quantitative assay of the activity of this enzyme should be carried out before its prescription. This deficiency is a recessive inherited disease linked to the X chromosome characterized by more or less low levels of enzymatic activity which depends on the genotype of the patients but not only because the phenotype depends on the level of activation of the X chromosome for each cell. Currently, obtaining a G6PD assay in French Guiana is a long process since it is done in mainland France and the pre-analytical conditions are quite demanding. Thus, in areas of transmission of P. vivax, patients usually have a bout of revival before being prescribed primaquine. This period includes: dosing G6PD at a distance from access, obtaining the result and then the nominal ATU to finally obtain and deliver the primaquine.
A Phase Ia Clinical Trial to Assess the Safety and Immunogenicity of the Blood-stage Malaria Candidate...
MalariaFalciparumThis is an open-label, single-centre Phase I P. falciparum blood-stage vaccine trial to assess the safety and immunogenicity and efficacy of the candidate malaria vaccines R78C and RH5.1 formulated in adjuvant Matrix-M