Studies of Transgenic Mosquitoes in Disease-Endemic Countries: Preparation of Containment Facilities

Controlled human malaria infection: overview and potential application in the evaluation of transmission-blocking interventions in malaria-endemic areas

Controlled human malaria infection (CHMI) involves the intentional infection of healthy individuals with malaria parasites, close observation of the volunteers, and clearance of the parasite at a predetermined endpoint. Depending on the need, CHMI can be initiated by either sporozoites or the administration of parasite-infected erythrocytes, with each of the two systems offering different advantages and caveats. Among other uses, CHMI has proven to be a useful tool for the evaluation of new malaria interventions, particularly vaccines and drugs. The majority of CHMI studies have been conducted in Europe, the USA and Australia, with only a handful of studies conducted in malaria-endemic countries. The slow adoption of CHMI in malaria-endemic countries may be attributed to a lack of infrastructure and expertise to conduct studies in malaria-endemic countries and the risk of undue influence and coercion as a result of volunteers' vulnerability due to a lack of education and financial situation. With the need to generate results relevant to the target populations, there has recently been an increase in CHMI studies that are being conducted in malaria-endemic countries. The use of CHMI models for the evaluation of preerythrocytic and blood-stage malaria interventions has been attempted in malaria-endemic countries with great success. There is a need for the adoption of a CHMI model for the evaluation of transmission-blocking interventions in malaria-endemic countries. The establishment of such a model in malaria-endemic countries will facilitate the selection of potential transmission-blocking intervention (TBI) candidates and accelerate their development. Here is an overview of CHMI, key challenges and ethical considerations in adopting CHMI for the evaluation of malaria transmission-blocking interventions in malaria-endemic countries.

Procedural legitimacy: co-developing a community agreement model for genetic approaches research to malaria control in Africa

With reductions in the malaria burden stalling in the past years, gene drive holds promise as a novel way of reducing disease transmission. Governance and decision-making processes are pivotal aspects of the legitimate adoption of this technology. Here, the authors explore Target Malaria's journey in developing a community agreement model for the release of non-gene drive genetically modified mosquitoes. They describe the iterative development of the model, including consultations with experts, stakeholder engagement, and alignment with principles of procedural justice. Several challenges were identified during its development, including defining communities, ensuring adequate information, consultation, monitoring, and achieving a common decision between dissenting and consenting viewpoints. They underscore the complexity of developing a legitimate model and emphasize the importance of transparency, procedural legitimacy, and adherence to ethical principles. This paper does not describe the model itself, which will be the subject of another paper. Instead it focuses on the process, to share this experience with other projects-those working with gene drive, or any other projects requiring a community-level decision-making process. The model builds on Target Malaria's experience with the release of genetically modified sterile male mosquitoes, to address the challenges posed by modified mosquitoes which are fertile and would therefore be expected to persist longer in the environment and spread further than the sterile male mosquito strains. While the level of spread and persistence of these non gene drive, but fertile, modified mosquitoes are expected to be substantially lower than those of the gene drive mosquitoes, the process is an essential advance in accommodating the broader geographical and temporal concerns associated with the more permanent spread of gene drive mosquitoes. The work described here constitutes part of the evolution of a community agreement process that could be applied to proposals for releases of gene drive mosquitoes for malaria control. In describing this process, Target Malaria hopes to contribute to the ongoing dialogue on good practices for community agreement engagement in research for genetic vector control approaches and to share the experience of building legitimacy while designing such agreement models.

Operationalizing stakeholder engagement for gene drive research in malaria elimination in Africa—translating guidance into practice

Gene drive mosquitoes are increasingly considered a potential transformational tool for vector control of malaria mosquitoes. As part of efforts to promote responsible research in this field, a number of guidance documents have been published by the World Health Organization, National Academies and expert groups. While virtually all recent guidance documents on gene drive research stress the importance of stakeholder engagement activities, no specific guidelines on implementing them have been established. Target Malaria, a not-for-profit research consortium developing a vector-control gene drive approach to eliminate malaria, has reflected on how its stakeholder engagement strategy translates engagement guidance documents into practice. The project analysed and addressed the tension between the context specificities and the international recommendations. The engagement strategy combines published recommendations for responsible gene drive research, information collected from the local context where the project operates and a set of principles guiding the choices made. This strategy was first developed during the early phases of the project’s research, years ahead of any activities with gene drive mosquitoes in those countries of operations. These earlier activities, and their related engagement, allow the project to develop and adapt an engagement strategy appropriate for potential gene drive research in its field site countries. This paper offers a description of a stakeholder engagement strategy operationalization based on (1) adaptation to stakeholder preferences, (2) inclusiveness and (3) empowerment and accountability. The authors hope to offer concrete examples to support other projects with the development and implementation of their engagement strategies with particular attention to the co-development principle.

Preparing an Insectary in Burkina Faso to Support Research in Genetic Technologies for Malaria Control

The Institut de Recherche en Sciences de la Santé (IRSS) of Burkina Faso, West Africa, was the first African institution to import transgenic mosquitoes for research purposes. A shift from the culture of mosquito research to regulated biotechnology research and considerable management capacity is needed to set up and run the first insectary for transgenic insects in a country that applied and adapted the existing biosafety framework, first developed for genetically modified (GM) crops, to this new area of research. The additional demands arise from the separate regulatory framework for biotechnology, referencing the Cartagena Protocol on Biosafety, and the novelty of the research strain, making public understanding and acceptance early in the research pathway important. The IRSS team carried out extensive preparations following recommendations for containment of GM arthropods and invested efforts in local community engagement and training with scientific colleagues throughout the region. Record keeping beyond routine practice was established to maintain evidence related to regulatory requirements and risk assumptions. The National Biosafety Agency of Burkina Faso, Agence Nationale de Biosécurité (ANB), granted the permits for import of the self-limiting transgenic mosquito strain, which took place in November 2016, and for conducting studies in the IRSS facility in Bobo-Dioulasso. Compliance with permit terms and conditions of the permits and study protocols continued until the conclusion of studies, when the transgenic colonies were terminated. All this required close coordination between management and the insectary teams, as well as others. This article outlines the experiences of the IRSS to support others undertaking such studies. The IRSS is contributing to the ongoing development of genetic technologies for malaria control, as a partner of Target Malaria. The ultimate objective of the innovation is to reduce malaria transmission by using GM mosquitoes of the same species released to reduce the disease-vectoring native populations of Anopheles gambiae s.l.

Small-scale release of non-gene drive mosquitoes in Burkina Faso: from engagement implementation to assessment, a learning journey

Background

Innovative tools are needed to complement the existing approach for malaria elimination. Gene drive mosquitoes are one potential new technology in the control of malaria vectors. Target Malaria is one of the research projects developing this technology, and in July 2019, the project proceeded to an important step for this evaluation pathway: the small-scale release of non-gene drive sterile male mosquitoes in a village in Burkina Faso. In addition to the entomological and laboratory work to prepare for this important milestone, significant community and stakeholder engagement work was done. The existing guidelines on gene drive mosquito provide an overall framework for such engagement work. However, they do not provide a road map on how to proceed or what benchmarks should be used to assess this work.

Methods

This study provides a review of engagement activities relevant to field trials on non-gene drive genetically-modified mosquitoes as well as an assessment framework—using both qualitative and quantitative studies as well as an audit procedure. The latter was implemented to evaluate whether the release activities could proceed with the appropriate level of agreement from the community.

Results

This paper shows the importance of this first phase of work to innovate and learn about engagement processes for responsible research in the field of genetic approaches for malaria vector control. The function of these assessments is crucial for the learning agenda. The assessments demonstrated ways to increase understanding and ensure effective progress with field studies and, therefore, the pathway for responsible research.

Conclusion

Gene drive technology is increasingly considered as a promising approach to control vector borne diseases, in particular malaria. Stakeholders’ involvement in this research process is one of the recurring requirements in international guidance documents. With this paper Target Malaria offers an opportunity to explore the practical achievements and challenges of stakeholder engagement during early phases of a technology evaluation, and in particular how it implemented an assessment framework to learn from its experience.

Experimenting with co-development: A qualitative study of gene drive research for malaria control in Mali

We investigate how technology 'co-development' (between researchers, stakeholders and local communities) is framed in practice by those developing gene drive mosquitos for malaria eradication. Our case study focuses on UK and Mali-based researchers planning to undertake the first field trials in Mali of gene drive mosquitos for malaria control. While they and the wider gene drive research community are explicitly committed to the principle of co-development, how this is framed and practiced is not clear. Through qualitative analysis of 34 interviews complemented by observation and documentary research conducted in 2018, we identify and compare ten framings of co-development mobilised by UK and Malian researchers and stakeholders. For Malians, co-development reflected Mali's broader socio-political context and a desire for African scientific independence and leadership. It was mobilised to secure community and stakeholder support for gene drive mosquito field trials, through outreach, building local scientific capacity and developing those institutions (e.g. regulatory) necessary for field trials to go ahead. For UK participants, co-development was also concerned with scientific capacity-building, knowledge exchange between researchers, and stakeholder and community outreach to secure consent for field trials. Overall, our findings suggest co-development is opening up previously expert-dominated spaces as researchers attempt to take responsibility for the societal implications of their work. However, its main function is as a project management tool to enable and instrumentally support technological development, field trials and eventual deployment. This function extends into areas which are traditionally the responsibility of the state, such as regulatory development, facilitated by Mali's fragile political and economic situation. Paradoxically, co-development simultaneously depoliticises gene drive, masking power relations and closing down substantive debate and agency. Characterised by extreme poverty, conflict and weak institutions, Mali may become a site for technological experimentation where there is little interrogation of gene drive or its governance.

Auditing Preparedness for Vector Control Field Studies

The value of baseline entomological data to any future area-wide release campaign relies on the application of consistent methods to produce results comparable across different times and places in a stepwise progression to larger releases. Traditionally, standard operating procedures (SOPs) and operational plans support this consistency and, thus, the validity of emergent data. When release plans include transgenic mosquitoes for vector control or other novel beneficial insects, additional factors come into play such as biosafety permits, stakeholder acceptance, and ethics approval, which require even greater coordination and thoroughness. An audit approach was developed to verify the correct use of SOPs and appropriate performance of tasks during mosquito mark, release, recapture (MRR) studies. Audit questions matched SOPs, permit terms and conditions, and other key criteria, and can be used to support subsequent “spot check” verification by field teams. An external team of auditors, however, was found to be effective for initial checks in this example before the use of a transgenic strain of laboratory mosquitoes. We recommend similar approaches for field studies using release of novel beneficial insects, to ensure useful and valid data as an outcome and to support confidence in the rigor of the step-wise process.

Containment Studies of Transgenic Mosquitoes in Disease Endemic Countries: The Broad Concept of Facilities Readiness

Genetic strategies for large scale pest or vector control using modified insects are not yet operational in Africa, and currently rely on import of the modified strains to begin preliminary, contained studies. Early involvement of research teams from participating countries is crucial to evaluate candidate field interventions. Following the recommended phased approach for novel strategies, evaluation should begin with studies in containment facilities. Experiences to prepare facilities and build international teams for research on transgenic mosquitoes revealed some important organizing themes underlying the concept of "facilities readiness," or the point at which studies in containment may proceed, in sub-Saharan African settings. First, "compliance" for research with novel or non-native living organisms was defined as the fulfillment of all legislative and regulatory requirements. This is not limited to regulations regarding use of transgenic organisms. Second, the concept of "colony utility" was related to the characteristics of laboratory colonies being produced so that results of studies may be validated across time, sites, and strains or technologies; so that the appropriate candidate strains are moved forward toward field studies. Third, the importance of achieving "defensible science" was recognized, including that study conclusions can be traced back to evidence, covering the concerns of various stakeholders over the long term. This, combined with good stewardship of resources and appropriate funding, covers a diverse set of criteria for declaring when "facilities readiness" has been attained. It is proposed that, despite the additional demands on time and resources, only with the balance of and rigorous achievement of each of these organizing themes can collaborative research into novel strategies in vector or pest control reliably progress past initial containment studies.