Transmission Blocking Activity of Low-dose Tafenoquine in Healthy Volunteers Experimentally Infected With Plasmodium falciparum.

BACKGROUND: Blocking the transmission of parasites from humans to mosquitoes is a key component of malaria control. Tafenoquine exhibits activity against all stages of the malaria parasite and may have utility as a transmission blocking agent. We aimed to characterize the transmission blocking activity of low-dose tafenoquine. METHODS: Healthy adults were inoculated with Plasmodium falciparum 3D7-infected erythrocytes on day 0. Piperaquine was administered on days 9 and 11 to clear asexual parasitemia while allowing gametocyte development. A single 50-mg oral dose of tafenoquine was administered on day 25. Transmission was determined by enriched membrane feeding assays predose and at 1, 4, and 7 days postdose. Artemether-lumefantrine was administered following the final assay. Outcomes were the reduction in mosquito infection and gametocytemia after tafenoquine and safety parameters. RESULTS: Six participants were enrolled, and all were infective to mosquitoes before tafenoquine, with a median 86% (range, 22-98) of mosquitoes positive for oocysts and 57% (range, 4-92) positive for sporozoites. By day 4 after tafenoquine, the oocyst and sporozoite positivity rate had reduced by a median 35% (interquartile range [IQR]: 16-46) and 52% (IQR: 40-62), respectively, and by day 7, 81% (IQR 36-92) and 77% (IQR 52-98), respectively. The decline in gametocyte density after tafenoquine was not significant. No significant participant safety concerns were identified. CONCLUSIONS: Low-dose tafenoquine (50 mg) reduces P. falciparum transmission to mosquitoes, with a delay in effect.

Safety, infectivity and immunogenicity of a genetically attenuated blood-stage malaria vaccine.

BACKGROUND: There is a clear need for novel approaches to malaria vaccine development. We aimed to develop a genetically attenuated blood-stage vaccine and test its safety, infectivity, and immunogenicity in healthy volunteers. Our approach was to target the gene encoding the knob-associated histidine-rich protein (KAHRP), which is responsible for the assembly of knob structures at the infected erythrocyte surface. Knobs are required for correct display of the polymorphic adhesion ligand P. falciparum erythrocyte membrane protein 1 (PfEMP1), a key virulence determinant encoded by a repertoire of var genes. METHODS: The gene encoding KAHRP was deleted from P. falciparum 3D7 and a master cell bank was produced in accordance with Good Manufacturing Practice. Eight malaria naïve males were intravenously inoculated (day 0) with 1800 (2 subjects), 1.8 × 105 (2 subjects), or 3 × 106 viable parasites (4 subjects). Parasitemia was measured using qPCR; immunogenicity was determined using standard assays. Parasites were rescued into culture for in vitro analyses (genome sequencing, cytoadhesion assays, scanning electron microscopy, var gene expression). RESULTS: None of the subjects who were administered with 1800 or 1.8 × 105 parasites developed parasitemia; 3/4 subjects administered 3× 106 parasites developed significant parasitemia, first detected on days 13, 18, and 22. One of these three subjects developed symptoms of malaria simultaneously with influenza B (day 17; 14,022 parasites/mL); one subject developed mild symptoms on day 28 (19,956 parasites/mL); and one subject remained asymptomatic up to day 35 (5046 parasites/mL). Parasitemia rapidly cleared with artemether/lumefantrine. Parasitemia induced a parasite-specific antibody and cell-mediated immune response. Parasites cultured ex vivo exhibited genotypic and phenotypic properties similar to inoculated parasites, although the var gene expression profile changed during growth in vivo. CONCLUSIONS: This study represents the first clinical investigation of a genetically attenuated blood-stage human malaria vaccine. A P. falciparum 3D7 kahrp- strain was tested in vivo and found to be immunogenic but can lead to patent parasitemia at high doses. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (number: ACTRN12617000824369 ; date: 06 June 2017).

Development and evaluation of a new Plasmodium falciparum 3D7 blood stage malaria cell bank for use in malaria volunteer infection studies.

BACKGROUND: New anti-malarial therapeutics are required to counter the threat of increasing drug resistance. Malaria volunteer infection studies (VIS), particularly the induced blood stage malaria (IBSM) model, play a key role in accelerating anti-malarial drug development. Supply of the reference 3D7-V2 Plasmodium falciparum malaria cell bank (MCB) is limited. This study aimed to develop a new MCB, and compare the safety and infectivity of this MCB with the existing 3D7-V2 MCB, in a VIS. A second bank (3D7-V1) developed in 1995 was also evaluated. METHODS: The 3D7-V2 MCB was expanded in vitro using a bioreactor to produce a new MCB designated 3D7-MBE-008. This bank and 3D7-V1 were then evaluated using the IBSM model, where healthy participants were intravenously inoculated with blood-stage parasites. Participants were treated with artemether-lumefantrine when parasitaemia or clinical thresholds were reached. Safety, infectivity and parasite growth and clearance were evaluated. RESULTS: The in vitro expansion of 3D7-V2 produced 200 vials of the 3D7-MBE-008 MCB, with a parasitaemia of 4.3%. This compares to 0.1% in the existing 3D7-V2 MCB, and < 0.01% in the 3D7-V1 MCB. All four participants (two per MCB) developed detectable P. falciparum infection after inoculation with approximately 2800 parasites. For the 3D7-MBE-008 MCB, the parasite multiplication rate of 48 h (PMR48) using non-linear mixed effects modelling was 34.6 (95% CI 18.5-64.6), similar to the parental 3D7-V2 line; parasitaemia in both participants exceeded 10,000/mL by day 8. Growth of the 3D7-V1 was slower (PMR48 of 11.5 [95% CI 8.5-15.6]), with parasitaemia exceeding 10,000 parasites/mL on days 10 and 8.5. Rapid parasite clearance followed artemether-lumefantrine treatment in all four participants, with clearance half-lives of 4.01 and 4.06 (weighted mean 4.04 [95% CI 3.61-4.57]) hours for 3D7-MBE-008 and 4.11 and 4.52 (weighted mean 4.31 [95% CI 4.16-4.47]) hours for 3D7-V1. A total of 59 adverse events occurred; most were of mild severity with three being severe in the 3D7-MBE-008 study. CONCLUSION: The safety, growth and clearance profiles of the expanded 3D7-MBE-008 MCB closely resemble that of its parent, indicating its suitability for future studies. TRIAL REGISTRATION: Australian New Zealand Clinical Trials registry numbers: P3487 (3D7-V1): ACTRN12619001085167. P3491 (3D7-MBE-008): ACTRN12619001079134.

Development and Evaluation of a Recovery College Fidelity Measure.

OBJECTIVE: Recovery Colleges are widespread, with little empirical research on their key components. This study aimed to characterize key components of Recovery Colleges and to develop and evaluate a developmental checklist and a quantitative fidelity measure. METHODS: Key components were identified through a systematized literature review, international expert consultation (n = 77), and semistructured interviews with Recovery College managers across England (n = 10). A checklist was developed and refined through semistructured interviews with Recovery College students, trainers, and managers (n = 44) in 3 sites. A fidelity measure was adapted from the checklist and evaluated with Recovery College managers (n = 39, 52%), clinicians providing psychoeducational courses (n = 11), and adult education lecturers (n = 10). RESULTS: Twelve components were identified, comprising 7 nonmodifiable components (Valuing Equality, Learning, Tailored to the Student, Coproduction of the Recovery College, Social Connectedness, Community Focus, and Commitment to Recovery) and 5 modifiable components (Available to All, Location, Distinctiveness of Course Content, Strengths Based, and Progressive). The checklist has service user student, peer trainer, and manager versions. The fidelity measure meets scaling assumptions and demonstrates adequate internal consistency (0.72), test-retest reliability (0.60), content validity, and discriminant validity. CONCLUSIONS: Coproduction and an orientation to adult learning should be the highest priority in developing Recovery Colleges. The creation of the first theory-based empirically evaluated developmental checklist and fidelity measure (both downloadable at researchintorecovery.com/recollect ) for Recovery Colleges will help service users understand what Recovery Colleges offer, will inform decision making by clinicians and commissioners about Recovery Colleges, and will enable formal evaluation of their impact on students.

A bioreactor system for the manufacture of a genetically modified Plasmodium falciparum blood stage malaria cell bank for use in a clinical trial.

BACKGROUND: Although the use of induced blood stage malaria infection has proven to be a valuable tool for testing the efficacy of vaccines and drugs against Plasmodium falciparum, a limiting factor has been the availability of Good Manufacturing Practice (GMP)-compliant defined P. falciparum strains for in vivo use. The aim of this study was to develop a cost-effective method for the large-scale production of P. falciparum cell banks suitable for use in clinical trials. METHODS: Genetically-attenuated parasites (GAP) were produced by targeted deletion of the gene encoding the knob associated histidine rich protein (kahrp) from P. falciparum strain 3D7. A GAP master cell bank (MCB) was manufactured by culturing parasites in an FDA approved single use, closed system sterile plastic bioreactor. All components used to manufacture the MCB were screened to comply with standards appropriate for in vivo use. The cryopreserved MCB was subjected to extensive testing to ensure GMP compliance for a phase 1 investigational product. RESULTS: Two hundred vials of the GAP MCB were successfully manufactured. At harvest, the GAP MCB had a parasitaemia of 6.3%, with 96% of parasites at ring stage. Testing confirmed that all release criteria were met (sterility, absence of viral contaminants and endotoxins, parasite viability following cryopreservation, identity and anti-malarial drug sensitivity of parasites). CONCLUSION: Large-scale in vitro culture of P. falciparum parasites using a wave bioreactor can be achieved under GMP-compliant conditions. This provides a cost-effective methodology for the production of malaria parasites suitable for administration in clinical trials.

Best practice framework for Patient and Public Involvement (PPI) in collaborative data analysis of qualitative mental health research: methodology development and refinement.

BACKGROUND: Patient and Public Involvement (PPI) in mental health research is increasing, especially in early (pre-funding) stages. PPI is less consistent in later stages, including in analysing qualitative data. The aims of this study were to develop a methodology for involving PPI co-researchers in collaboratively analysing qualitative mental health research data with academic researchers, to pilot and refine this methodology, and to create a best practice framework for collaborative data analysis (CDA) of qualitative mental health research. METHODS: In the context of the RECOLLECT Study of Recovery Colleges, a critical literature review of collaborative data analysis studies was conducted, to identify approaches and recommendations for successful CDA. A CDA methodology was developed and then piloted in RECOLLECT, followed by refinement and development of a best practice framework. RESULTS: From 10 included publications, four CDA approaches were identified: (1) consultation, (2) development, (3) application and (4) development and application of coding framework. Four characteristics of successful CDA were found: CDA process is co-produced; CDA process is realistic regarding time and resources; demands of the CDA process are manageable for PPI co-researchers; and group expectations and dynamics are effectively managed. A four-meeting CDA process was piloted to co-produce a coding framework based on qualitative data collected in RECOLLECT and to create a mental health service user-defined change model relevant to Recovery Colleges. Formal and informal feedback demonstrated active involvement. The CDA process involved an extra 80 person-days of time (40 from PPI co-researchers, 40 from academic researchers). The process was refined into a best practice framework comprising Preparation, CDA and Application phases. CONCLUSIONS: This study has developed a typology of approaches to collaborative analysis of qualitative data in mental health research, identified from available evidence the characteristics of successful involvement, and developed, piloted and refined the first best practice framework for collaborative analysis of qualitative data. This framework has the potential to support meaningful PPI in data analysis in the context of qualitative mental health research studies, a previously neglected yet central part of the research cycle.

Investigating the impact of the COVID-19 pandemic on recovery colleges: multi-site qualitative study.

BACKGROUND: During the COVID-19 pandemic, mental health problems increased as access to mental health services reduced. Recovery colleges are recovery-focused adult education initiatives delivered by people with professional and lived mental health expertise. Designed to be collaborative and inclusive, they were uniquely positioned to support people experiencing mental health problems during the pandemic. There is limited research exploring the lasting impacts of the pandemic on recovery college operation and delivery to students. AIMS: To ascertain how the COVID-19 pandemic changed recovery college operation in England. METHOD: We coproduced a qualitative interview study of recovery college managers across the UK. Academics and co-researchers with lived mental health experience collaborated on conducting interviews and analysing data, using a collaborative thematic framework analysis. RESULTS: Thirty-one managers participated. Five themes were identified: complex organisational relationships, changed ways of working, navigating the rapid transition to digital delivery, responding to isolation and changes to accessibility. Two key pandemic-related changes to recovery college operation were highlighted: their use as accessible services that relieve pressure on mental health services through hybrid face-to-face and digital course delivery, and the development of digitally delivered courses for individuals with mental health needs. CONCLUSIONS: The pandemic either led to or accelerated developments in recovery college operation, leading to a positioning of recovery colleges as a preventative service with wider accessibility to people with mental health problems, people under the care of forensic mental health services and mental healthcare staff. These benefits are strengthened by relationships with partner organisations and autonomy from statutory healthcare infrastructures.

The production of Necator americanus larvae for use in experimental human infection.

BACKGROUND: Although there is unprecedented interest in experimental human hookworm infection, details of hookworm manufacture and characterisation have been sparsely reported. In this report, we detail the production and characterisation of Necator americanus larvae for use in a recently published clinical trial. METHODS: Faeces was obtained from an experimentally infected donor. Faecal hookworm DNA was determined by quantitative PCR. Paired samples were incubated in either sterile water or sterile water mixed with antimicrobials (amphotericin and gentamicin). Coproculture was performed by modified Harada-Mori method. The harvested larvae were then processed in either sterile water or antiseptic solution. Larval yield was then calculated (larvae per gram), larval viability was determined by thermally induced motility assay and microbial burden was determined at the day of harvest, at 48 h and at 7 days. RESULTS: Twenty-eight faecal cultures were performed over 16 months. The faecal hookworm DNA content was variable over this time. There was no association of larval yield with faecal hookworm DNA content. Pre-treatment of faeces with antimicrobials did not influence larval yield. Larval motility was 85.3% (95% CI 79.3-91.3%). Incubation of larvae in antiseptics did not reduce viability at 14 days with a marginal mean of 68.6% (95% CI 59.1-78.1%) washed in water vs. 63.3% (95% CI 53.8 - 72.9%) when incubated in betadine (p = 0.38). Larvae washed in sterile water did not meet microbial bioburden criteria. Incubation in antiseptic resulted in acceptable microbial bioburden at 48 h but not at 7 days. Although the addition of gentamicin did reduce the microbial bio-burden acceptable levels, it was found to significantly lower larval motility at 7 days compared to incubation in sterile water and motility at 7 days 37.8% (95% CI 4.7-70.9%) vs. 67.3% (95% CI 35.2-99.3%, p < 0.001), respectively. CONCLUSIONS: Despite standardised culture methodologies and the use of a single donor, larval yield varied considerably between batches and had no association with faecal hookworm DNA. Larval viability decreases over time and the age of larvae at time of use are likely to be important. Microbial bioburden maybe temporarily reduced by incubation in antiseptics and has little effect on viability. Incubation of larvae in gentamicin is effective at reducing microbial bioburden but is deleterious to larval viability.

Mechanisms of Action and Outcomes for Students in Recovery Colleges.

OBJECTIVE: Recovery colleges are widespread, with little empirical research on how they work and the outcomes they produce. This study aimed to coproduce a change model characterizing mechanisms of action (how they work) and outcomes (their impact) for mental health service users who attend recovery colleges. METHODS: A systematized review identified all publications about recovery colleges. Inductive collaborative data analysis of 10 key publications by academic researchers and coresearchers with lived experience informed a theoretical framework for mechanisms of action and student outcomes, which was refined through deductive analysis of 34 further publications. A change model was coproduced and refined through stakeholder interviews (N=33). RESULTS: Four mechanisms of action for recovery colleges were identified: empowering environment (safety, respect, and supporting choices), enabling different relationships (power, peers, and working together), facilitating personal growth (for example, coproduced learning, strengths, and celebrating success), and shifting the balance of power through coproduction and reducing power differentials. Outcomes were change in the student (for example, self-understanding and self-confidence) and changes in the student's life (for example, occupational, social, and service use). A coproduced change model mapping mechanisms of action to outcomes was created. CONCLUSIONS: Key features differentiate recovery colleges from traditional services, including an empowering environment, enabling relationships, and growth orientation. Service users who lack confidence, those with whom services struggle to engage, those who will benefit from exposure to peer role models, and those lacking social capital may benefit most. As the first testable characterization of mechanisms and outcomes, the change model allows formal evaluation of recovery colleges.