Regulation of genetically engineered (GE) mosquitoes as a public health tool: a public health ethics analysis

BACKGROUND

In recent years, genetically engineered (GE) mosquitoes have been proposed as a public health measure against the high incidence of mosquito-borne diseases among the poor in regions of the global South. While uncertainties as well as risks for humans and ecosystems are entailed by the open-release of GE mosquitoes, a powerful global health governance non-state organization is funding the development of and advocating the use of those bio-technologies as public health tools. In August 2016, the US Food and Drug Agency (FDA) approved the uncaged field trial of a GE Aedes aegypti mosquito in Key Haven, Florida. The FDA's decision was based on its assessment of the risks of the proposed experimental public health research project. The FDA is considered a global regulatory standard setter. So, its approval of the uncaged field trial could be used by proponents of GE mosquitoes to urge countries in the global South to permit the use of those bio-technologies.

METHOD

From a public health ethics perspective, this paper evaluates the FDA's 2016 risk assessment of the proposed uncaged field trial of the GE mosquito to determine whether it qualified as a realistic risk evaluation.

RESULTS

The FDA's risk assessment of the proposed uncaged field trial did not proximate the conditions under which the GE mosquitoes would be used in regions of the global South where there is a high prevalence of mosquito-borne diseases.

CONCLUSION

Given that health and disease have political-economic determinants, whether a risk assessment of a product is realistic or not particularly matters with respect to interventions meant for public health problems that disproportionately impact socio-economically marginalized populations. If ineffective public health interventions are adopted based on risk evaluations that do not closely mirror the conditions under which those products would actually be used, there could be public health and ethical costs for those populations.

From the Lab to the Last Mile: Deploying Transgenic Approaches Against Mosquitoes

Ingenious exploitation of transgenic approaches to produce malaria resistant or sterile mosquitoes, or hypervirulent mosquito pathogens, has produced many potential solutions to vector borne diseases. However, in spite of technological feasibility, it has not been determined how well these new methods will work, and how they should be tested and regulated. Some self-limiting transgenic fungal pathogens and mosquitoes are almost field ready, and may be easier to regulate than self-sustaining strategies. However, they require repeat sales and so must show business viability; low-cost mass production is just one of a number of technical constraints that are sometimes treated as an afterthought in technology deployment. No transgenic self-sustaining approach to anopheline control has ever been deployed because of unresolved ethical, social and regulatory issues. These overlapping issues include: 1) the transparency challenge, which requires public discourse, particularly in Africa where releases are proposed, to determine what society is willing to risk given the potential benefits; 2) the transboundary challenge, self-sustaining mosquitoes or pathogens are potentially capable of crossing national boundaries and irreversibly altering ecosystems, and 3) the risk assessment challenge. The polarized debate as to whether these technologies will ever be used to save lives is ongoing; they will founder without a political answer as to how do we interpret the precautionary principle, as exemplified in the Cartagena protocol, in the global context of technological changes.

Spatiotemporal Controllability and Environmental Risk Assessment of Genetically Engineered Gene Drive Organisms from the Perspective of European Union Genetically Modified Organism Regulation

Gene drive organisms are a recent development created by using methods of genetic engineering; they inherit genetic constructs that are passed on to future generations with a higher probability than with Mendelian inheritance. There are some specific challenges inherent to the environmental risk assessment (ERA) of genetically engineered (GE) gene drive organisms because subsequent generations of these GE organisms might show effects that were not observed or intended in the former generations. Unintended effects can emerge from interaction of the gene drive construct with the heterogeneous genetic background of natural populations and/or be triggered by changing environmental conditions. This is especially relevant in the case of gene drives with invasive characteristics and typically takes dozens of generations to render the desired effect. Under these circumstances, "next generation effects" can substantially increase the spatial and temporal complexity associated with a high level of uncertainty in ERA. To deal with these problems, we suggest the introduction of a new additional step in the ERA of GE gene drive organisms that takes 3 criteria into account: the biology of the target organisms, their naturally occurring interactions with the environment (biotic and abiotic), and their intended biological characteristics introduced by genetic engineering. These 3 criteria are merged to form an additional step in ERA, combining specific "knowns" and integrating areas of "known unknowns" and uncertainties, with the aim of assessing the spatiotemporal controllability of GE gene drive organisms. The establishment of assessing spatiotemporal controllability can be used to define so-called "cut-off criteria" in the risk analysis of GE gene drive organisms: If it is likely that GE gene drive organisms escape spatiotemporal controllability, the risk assessment cannot be sufficiently reliable because it is not conclusive. Under such circumstances, the environmental release of the GE gene drive organisms would not be compatible with the precautionary principle (PP). Integr Environ Assess Manag 2020;16:555-568. © 2020 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).