Characterization of a novel merozoite surface antigen and potential vaccine target.

Introduction: Detailed analyses of genetic diversity, antigenic variability, protein localization and immunological responses are vital for the prioritization of novel malaria vaccine candidates. Comprehensive approaches to determine the most appropriate antigen variants needed to provide broad protection are challenging and consequently rarely undertaken.

Methods: Here, we characterized PF3D7_1136200, which we named Asparagine-Rich Merozoite Antigen (ARMA) based on the analysis of its sequence, localization and immunogenicity.

infection coinciding with the malaria vaccine candidate BK-SE36 administration interferes with the immune responses in Burkinabe children.

Background: A vaccine targeting the erythrocyte stages of could play a role in preventing clinical disease. BK-SE36 is a promising malaria vaccine candidate that has shown a good safety profile and immunological responses during field evaluations. It was observed that repeated natural infections could result in immune tolerance against SE36 molecule.

Using antenatal care as a platform for malaria surveillance data collection: study protocol.

Background: While many malaria-endemic countries have health management information systems that can measure and report malaria trends in a timely manner, these routine systems have limitations. Periodic community cross-sectional household surveys are used to estimate malaria prevalence and intervention coverage but lack geographic granularity and are resource intensive. Incorporating malaria testing for all women at their first antenatal care (ANC) visit (i.

Assessing the variability in experimental hut trials evaluating insecticide-treated nets against malaria vectors.

Experimental hut trials (EHTs) are used to evaluate indoor vector control interventions against malaria vectors in a controlled setting. The level of variability present in the assay will influence whether a given study is well powered to answer the research question being considered. We utilised disaggregated data from 15 previous EHTs to gain insight into the behaviour typically observed.

Hospital-based surveillance of severe paediatric malaria in two malaria transmission ecological zones of Burkina Faso.

Background: In the current context of tailoring interventions to maximize impact, it is important that current data of clinical epidemiology guide public health programmes and health workers in the management of severe disease. This study aimed at describing the burden of severe malaria at hospital level in two areas with distinct malaria transmission intensity.

Methods: A hospital-based surveillance was established in two regional hospitals located in two areas exposed to different malaria transmission.

Randomized, open-label, phase 2a study to evaluate the contribution of artefenomel to the clinical and parasiticidal activity of artefenomel plus ferroquine in African patients with uncomplicated Plasmodium falciparum malaria.

Background: The contribution of artefenomel to the clinical and parasiticidal activity of ferroquine and artefenomel in combination in uncomplicated Plasmodium falciparum malaria was investigated.

Methods: This Phase 2a, randomized, open-label, parallel-group study was conducted from 11th September 2018 to 6th November 2019 across seven centres in Benin, Burkina Faso, Gabon, Kenya, and Uganda. Patients aged ≥ 14-69 years with microscopically confirmed infection (≥ 3000 to ≤ 50,000 parasites/µL blood) were randomized 1:1:1:1 to 400 mg ferroquine, or 400 mg ferroquine plus artefenomel 300, 600, or 1000 mg, administered as a single oral dose.

African-specific polymorphisms in serine repeat antigen 5 in Uganda and Burkina Faso clinical samples do not interfere with antibody response to BK-SE36 vaccination.

BK-SE36, based on serine repeat antigen 5 (SERA5), is a blood-stage malaria vaccine candidate currently being evaluated in clinical trials. Phase 1 trials in Uganda and Burkina Faso have demonstrated promising safety and immunogenicity profiles. However, the genetic diversity of in Africa and the role of allele/variant-specific immunity remain a major concern.

Impact of physicochemical parameters of Aedes aegypti breeding habitats on mosquito productivity and the size of emerged adult mosquitoes in Ouagadougou City, Burkina Faso.

Background: Outbreaks of dengue fever caused by viruses transmitted by Aedes aegypti mosquitoes are repeated occurrences in West Africa. In recent years, Burkina Faso has experienced major dengue outbreaks, most notably in 2016 and 2017 when 80% of cases were recorded in Ouagadougou City (Central Health Region). In order to better understand the ecology of this vector and to provide information for use in developing control measures, a study on the characteristics of Aedes container breeding sites and the productivity of such sites, as measured by the abundance of immature stages and resultant adult body size, was undertaken in three health districts (Baskuy, Bogodogo and Nongremassom) of Ouagadougou.

Plasmodium malariae structure and genetic diversity in sub-Saharan Africa determined from microsatellite variants and linked SNPs in orthologues of antimalarial resistance genes.

Plasmodium malariae, a neglected human malaria parasite, contributes up to 10% of malaria infections in sub-Saharan Africa (sSA). Though P. malariae infection is considered clinically benign, it presents mostly as coinfections with the dominant P.

Impact of exposure to malaria and nutritional status on responses to the experimental malaria vaccine ChAd63 MVA ME-TRAP in 5-17 month-old children in Burkina Faso.

Unlabelled: The experimental malaria vaccine ChAd63 MVA ME-TRAP previously showed protective efficacy against infection in Phase IIa sporozoite challenge studies in adults in the United Kingdom and in a Phase IIb field efficacy trial in Kenyan adults. However, it failed to demonstrate efficacy in a phase IIb trial in 5-17 month-old children in an area of high malaria transmission in Burkina Faso. This secondary analysis investigated whether exposure to malaria or nutritional status might be associated with reduced responses to vaccination in this cohort.

A randomized controlled trial showing safety and efficacy of a whole sporozoite vaccine against endemic malaria.

A highly effective malaria vaccine remains elusive despite decades of research. sporozoite vaccine (PfSPZ Vaccine), a metabolically active, nonreplicating, whole parasite vaccine demonstrated safety and vaccine efficacy (VE) against endemic for 6 months in Malian adults receiving a five-dose regimen. Safety, immunogenicity, and VE of a three-dose regimen were assessed in adults in Balonghin, Burkina Faso in a two-component study: an open-label dose escalation trial with 32 participants followed by a double-blind, randomized, placebo-controlled trial (RCT) with 80 participants randomized to receive three doses of 2.

Effects of the free healthcare policy on health services' usage by children under 5 years in Burkina Faso: a controlled interrupted time-series analysis.

Objectives: This study aimed to analyse, at national level, the effects of the free healthcare policy for children on the use of health services by children under five in Burkina Faso. We hypothesised that this policy has led to an immediate and sustained increase in the use of health services for these children in the country.

Setting: We conducted a controlled interrupted time series.

Increased levels of anti-PfCSP antibodies in post-pubertal females versus males immunized with PfSPZ Vaccine does not translate into increased protective efficacy.

Background: While prior research has shown differences in the risk of malaria infection and sickness between males and females, little is known about sex differences in vaccine-induced immunity to malaria. Identifying such differences could elucidate important aspects of malaria biology and facilitate development of improved approaches to malaria vaccination.

Methods: Using a standardized enzyme-linked immunosorbent assay, IgG antibodies to the major surface protein on (Pf) sporozoites (SPZ), the Pf circumsporozoite protein (PfCSP), were measured before and two weeks after administration of a PfSPZ-based malaria vaccine (PfSPZ Vaccine) to 5-month to 61-year-olds in 11 clinical trials in Germany, the US and five countries in Africa, to determine if there were differences in vaccine elicited antibody response between males and females and if these differences were associated with differential protection against naturally transmitted Pf malaria (Africa) or controlled human malaria infection (Germany, the US and Africa).

Building the capacity of West African countries in Aedes surveillance: inaugural meeting of the West African Aedes Surveillance Network (WAASuN).

Arboviral diseases such as dengue, Zika and chikungunya transmitted by Aedes mosquitoes have been reported in 34 African countries. Available data indicate that in recent years there have been dengue and chikungunya outbreaks in the West Africa subregion, in countries including Côte d'Ivoire, Burkina Faso, Gabon, Senegal, and Benin. These viral diseases are causing an increased public health burden, which impedes poverty reduction and sustainable development.

Safety and immunogenicity of BK-SE36 in a blinded, randomized, controlled, age de-escalating phase Ib clinical trial in Burkinabe children.

Background: A blood-stage vaccine targeting the erythrocytic-stages of the malaria parasite could play a role to protect against clinical disease. Antibodies against the serine repeat antigen 5 (SE47 and SE36 domains) correlate well with the absence of clinical symptoms in sero-epidemiological studies. A previous phase Ib trial of the recombinant SE36 antigen formulated with aluminum hydroxyl gel (BK-SE36) was promising.

Multiple insecticide resistance and first evidence of V410L kdr mutation in Aedes (Stegomyia) aegypti (Linnaeus) from Burkina Faso.

The response to recent dengue outbreaks in Burkina Faso was insecticide-based, despite poor knowledge of the vector population's susceptibility to the insecticides used. Here, we report on the susceptibility to the main insecticide classes and identify important underlying mechanisms in Aedes aegypti populations in Ouagadougou and Banfora, in 2019 and 2020. Wild Ae.

Antimalarial drugs resistance genes of Plasmodium falciparum: a review.

Malaria remains the most common parasitic disease on the planet, with 229 million cases and 409,000 deaths worldwide in 2019, including 274,030 children under the age of 5. It is one of the most important infectious diseases in the world and its control is compromised by the spread of the parasite's resistance to antimalarial drugs. This study aims to review the literature of resistant Plasmodium falciparum genes over the past twenty years.

Inferring the epidemiological benefit of indoor vector control interventions against malaria from mosquito data.

The cause of malaria transmission has been known for over a century but it is still unclear whether entomological measures are sufficiently reliable to inform policy decisions in human health. Decision-making on the effectiveness of new insecticide-treated nets (ITNs) and the indoor residual spraying of insecticide (IRS) have been based on epidemiological data, typically collected in cluster-randomised control trials. The number of these trials that can be conducted is limited.

NK Cell Subset Redistribution and Antibody Dependent Activation after Ebola Vaccination in Africans.

Natural killer cells play an important role in the control of viral infections both by regulating acquired immune responses and as potent innate or antibody-mediated cytotoxic effector cells. NK cells have been implicated in control of Ebola virus infections and our previous studies in European trial participants have demonstrated durable activation, proliferation and antibody-dependent NK cell activation after heterologous two-dose Ebola vaccination with adenovirus type 26.ZEBOV followed by modified vaccinia Ankara-BN-Filo.

Knowledge translation and evidence generation to increase the impact of vector control in Burkina Faso, Cameroon and Malawi.

Lack of context-specific evidence and inadequate evidence-use for decision-making contribute to poor health. This paper reports on our work aimed at addressing the knowledge translation (KT) gap between evidence generators and users. We present our experiences of strengthening KT via technical advisory groups (TAGs) in parallel with increasing evidence generation through research fellowships and operational research.

Sympatric Populations of the Complex in Southwest Burkina Faso Evolve Multiple Diverse Resistance Mechanisms in Response to Intense Selection Pressure with Pyrethroids.

Pyrethroid resistance in the Anopheles vectors of malaria is driving an urgent search for new insecticides that can be used in proven vector control tools such as insecticide treated nets (ITNs). Screening for potential new insecticides requires access to stable colonies of the predominant vector species that contain the major pyrethroid resistance mechanisms circulating in wild populations. Southwest Burkina Faso is an apparent hotspot for the emergence of pyrethroid resistance in species of the Anopheles gambiae complex.

Comprehensive Genomic Discovery of Non-Coding Transcriptional Enhancers in the African Malaria Vector .

Almost all regulation of gene expression in eukaryotic genomes is mediated by the action of distant non-coding transcriptional enhancers upon proximal gene promoters. Enhancer locations cannot be accurately predicted bioinformatically because of the absence of a defined sequence code, and thus functional assays are required for their direct detection. Here we used a massively parallel reporter assay, Self-Transcribing Active Regulatory Region sequencing (STARR-seq), to generate the first comprehensive genome-wide map of enhancers in , a major African malaria vector in the Gambiae species complex.