Governance for Genetic Engineering to Control Disease Vectors in the Wild

Research is occurring to develop genetically engineered (GE) strains of insects or other animals that are specifically designed to push or “drive” genes into populations in the environment. Some motivations for doing so include reducing populations of pests that carry disease (population suppression) and immunizing beneficial or rare species against disease (population immunization). Gene drives, such as those based on the CRISPR-Cas9 system, have already been shown to work in laboratory-cage experiments with fruit flies and mosquitos, and several research groups are actively working towards deployment of gene drives for population suppression in the environment. These applications will be subject to some form of risk assessment and regulatory review in the United States, although the mechanisms and agencies involved are not entirely clear and will depend on the exact species and genes used.

In the United States, regulatory decisions have already been made for GE insects that contain self-killing systems, although they have not technically been based on gene drives. GE mosquitos, diamond back moths, pink bollworms, and Mediterranean fruit flies, all for self-population suppression, have been approved for release. Regulatory assessments for these GE insects can serve as clues for how information, data, and uncertainties are likely to be considered in federal decision-making about gene drives. In this presentation, the U.S. regulatory approach to GE insects is described and risk assessments done under current oversight regimes are examined for their adherence to principles of good risk governance. In particular, the case study of Aedes aegypti engineered for population suppression to reduce human disease is examined. This GE insect was cleared for field trials by FDA in 2016. The environmental assessment done for the FDA regulatory process and the surrounding procedures for risk analysis were found to be deficient according to principles of good risk governance.

Given the abilities of gene drive systems to permanently alter the composition of wild populations or eradicate them, it is crucial that FDA’s risk assessment process change before gene drive technologies are presented at the agency’s door. Regulatory decision-making should move away from hubris and towards humility, and in particular, adopt an alternative risk assessment paradigm that pays attention to procedural validity, such as the inclusion of diverse experts and stakeholders in the framing and conduct of the analysis and the explicit acknowledgment of the uncertainties in estimating probabilities of adverse events.