Considerations for Postrelease Environmental Safety Monitoring of Gene Drive-Modified Mosquitoes as a Tool for...

Progress on malaria elimination has stalled, especially in Africa where approximately 600,000 deaths occurred in 2024. Gene drive-modified mosquito (GDMM) technologies are a potentially transformational new tool to prevent malaria transmission by Anopheles mosquitoes. Gene drive-modified mosquito technologies have been successful in contained (caged) testing, and field testing is being planned. Gene drive-modified mosquitoes are designed to be more specific vector control tools than chemical insecticides. However, the potential for spread and persistence of engineered gene drive constructs within interbreeding mosquito populations has raised concerns about possible negative effects on biodiversity. Postrelease safety monitoring of GDMMs will be an important component of risk management, yet scientifically based strategies for evaluating the environmental safety of GDMMs are lacking. Drawing from experience with related technologies in use, we propose a systematic approach to safety monitoring that is risk proportionate, considers ecological priorities and stakeholder concerns, and is practicable to implement in malaria-endemic countries. Suggested methods aim to achieve maximal decision-making value within available resources. Indicators of possible adverse impacts are selected strategically according to ecological analyses using a transparent ranking system. Intensity and coverage of monitoring reflect characteristics of both the GDMMs and the ecological indicator species, with allowance for adjusting the plan in response to initial results, ongoing observations, and regulator feedback. Although developed for early field testing, the framework can also help to guide later phase research and postimplementation environmental monitoring of GDMMs for malaria control in Africa, and it may inform the development of other genetic biological control technologies.