Environmental Risk
Assessment of Gene Drives

Identifying Priorities for Risk Assessment of Gene Drive Mosquito

Overview

According to the World Health Organization’s World Malaria Report, almost 263 million estimated malaria cases occurred worldwide in 2023, with 94% of cases and 95% of deaths concentrated on the African continent. Alarmingly, and despite an increased public health focus on the elimination of malaria, it is becoming clear that many countries will not be able to achieve this goal without considering novel management approaches. One control strategy in the early stages of development is the use of gene drive mechanisms to suppress or replace vector mosquito populations.

Collaborators & Partners

Government of Australia
Foundation for the National Institutes of Health (FNIH)
New Partnership for African Development (NEPAD)
Organisation for Economic Co-operation and Development (OECD)

Understanding vector biology is an important component of any disease management strategy.

Current Work

Understanding Mosquito Biology to Inform Risk Assessment

Understanding vector biology is an important component of any disease management strategy. This knowledge will be essential for assessing the potential environmental risks that may be associated with the deployment of genetically engineered mosquitoes. To that end, the Agriculture & Food Systems Institute and representatives from the governments of Brazil and Mexico served as convening lead authors of the OECD’s first biology document for an insect species, Aedes aeqypti, which was published in 2018.

With the success of this first effort, a second mosquito biology document, describing Anopheles gambiae, is now underway. First proposed to the OECD by the New Partnership for African Development (NEPAD), the Agriculture & Food Systems Institute was pleased to be asked to co-lead the drafting group with NEPAD and the Government of Australia. With funding from the Foundation for the National Institutes of Health, we partnered with the OECD to convene a workshop in Addis Ababa, Ethiopia on March 14-15, 2019 that brought Anopheles experts together to start drafting the biology document. This author group continues its work, with the aim of having the final document published by the OECD in 2023.

Our Successes

Highlighting Genetic Strategies as an Approach to the Control of Invasive Species

Objective

Invasive species can pose a threat to the environment, agriculture, and human health. Most governmental approaches to control the spread of invasive species are focused on preventing new introductions, and efforts to address the control of invasive species once they have become established have met with limited success. Genetic strategies could offer a new opportunity to reduce or eliminate invasive species, and the need to explore different approaches to genetic biocontrol was identified.

Outcome

With the Organisation for Economic Co-operation and Development (OECD) Co-operative Research Programme: Biological Resource Management for Sustainable Agricultural Systems as a co-sponsor, the Agriculture and Food Systems Institute (AFSI) organized an in-person workshop on March 31, 2019 in Tarragona, Spain. The “Genetic Biocontrol for Invasive Species Workshop” highlighted different potential approaches to the control of invasive species that make use of transgenic and non-transgenic organisms designed for introduction into a target population to reduce or eliminate it, including:

Sterile Release for Eradication of Agricultural Insect Pests
Trojan Y Chromosome Eradication of Invasive Fish
Trojan Female Technique for Fruit Flies
Gene Drives for Eradication of Invasive Mice

The program also covered regulatory considerations for genetic biocontrol of invasive species, with discussions on:

Existing Regulatory Frameworks for Classical Biocontrol
Environmental Risk Assessment of Gene Drives
Historical Experience with Genetically Engineered Plants

A proceedings document focusing on the various biocontrol strategies presented at the workshop, which also offers insights on how these different methods may be viewed by risk assessors, regulators, and invasive species control program managers, was published in Frontiers in Bioengineering and Biotechnology on May 25, 2020. This review paper provides an overview of the state of genetic biocontrol and compares the different approaches with respect to:

The efficiency each affords as a genetic biocontrol tool.
The practical utility and cost/benefits associated with implementation.
The regulatory considerations that will need to be addressed for each.

Genetic Biocontrol for Invasive Species, Frontiers in Bioengineering and Biotechnology (2020)

Project Name:
Genetic Biocontrol for Invasive Species Workshop
Years:
2019-2020
Co-Sponsor:
Organisation for Economic Co-operation and Development (OECD) Co-operative Research Programme: Biological Resource Management for Sustainable Agricultural Systems
Parties:
Scientists, Regulators, Risk Assessors
Geography:
Spain

Conference on Mathematical Modeling of Gene Drives for Agriculture

Objective

Gene drive technology refers to any of a set of similar mechanisms that can be engineered to drive the inheritance of an allele through a population through higher transmission from parents to offspring than predicted by Mendelian inheritance. The potential applications of this technology in agriculture include uses for pest, disease, and weed control. Because field-testing of gene drives in the environment is problematic, mathematical modeling of gene drives was identified as a possible tool for improving the understanding of their potential environmental impacts. A need was identified to foster the exchange of ideas between regulatory agencies and scientists in the field of modeling for gene drive research.

Outcome

With funding from the United States Department of Agriculture National Institute for Food and Agriculture (USDA NIFA) Biotechnology Risk Assessment Research Grants (BRAG) Program, the Agriculture and Food Systems Institute (AFSI) first organized an online seminar series to prime audiences and stakeholders, with talks, spaced one month apart, on the following topics:

Adding Biology to Mathematical Models of Gene Drive Spread in Populations: A Case Study of Engineered Underdominance (March 22, 2019)
Simple and Complex Models: Their Roles in the Evaluation of Gene Drives (April 22, 2019)
Informing Risk Assessment with the Mosquito Gene Drive Explorer (May 20, 2019)

Having provided baseline information to facilitate discussions during the event, AFSI convened regulators, risk assessors, modelers, and biologists who understand gene drive technology for the Gene Drive Modeling Conference in Washington, DC on June 11-12, 2019. During the by-invitation-only event, participants:

Discussed the applicability of models for the environmental risk assessment of gene drive organisms.
Identified criteria for establishing the quality of information needed to inform future risk assessments of gene drives.
Exchanged ideas with representatives

Video Recordings of the 2019 Gene Drive Seminar Series

Project Name:
Gene Drive Modeling Conference and Webinar Series
Year:
2019
Funding:
United States Department of Agriculture National Institute for Food and Agriculture (USDA NIFA) Biotechnology Risk Assessment Research Grants (BRAG) Program
Parties:
Regulators, Risk Assessors, Modelers, and Biologists
Geography:
USA

Consultation Meetings on Problem Formulation for ERA of Gene Drive Mosquitoes

Objective

Vector biologists have long appreciated the potential of gene drives as tools for reducing or modifying populations of the world’s deadliest vectors, such as Anopheles gambiae and Aedes aegypti. With advances in genetic manipulation technology, numerous strategies have demonstrated the proof of principle for making functional gene drives under laboratory conditions. The African Union recognized gene drive as an emerging technology with great potential for contributing significantly to Africa’s development and emphasized that risk assessments will be essential for development of gene drive technologies.

The New Partnership for African Development (NEPAD) identified a need to initiate discussions concerning the processes by which environmental risk assessments (ERA) should be conducted for gene drive mosquitoes and took steps to organize regional consultations on the potential use of gene drives to combat malaria transmission through vector suppression, with the aim of providing participants with:

The most current information about research on mosquito gene drive technology.
The problem formulation process and its function in environmental risk assessments.
The opportunity to consider possible hazards and potential pathways to harm associated with the use of gene drive mosquitoes for malaria control in Africa.

Outcome

At the request of NEPAD, the Agriculture and Food Systems Institute (AFSI) assisted in setting the agenda for the scientific programs and guided participants through a problem formulation exercise to inform future work on risk assessment. The four regional consultations listed below were conducted between October 2016 and February 2018 to serve as an introduction to the basic principles of environmental risk assessment:

Central Africa Consultative Meeting · February 2018 in Gabon
East Africa Consultative Meeting · June 2017 in Kenya
Southern Africa Consultative Meeting · June 2017 in Botswana
West Africa Consultative Meeting · October 2016 in Ghana

The regional consultations provided a critical opportunity to hear from regional risk assessors and stakeholders regarding potential risks that may be associated with deploying gene drive technology for this purpose. Participants in the workshops identified human health and biodiversity as being relevant “broad protection goals.” Results of the deliberations provided insight into the concerns of African participants at an early stage in the development of gene drive mosquitos that should be instructive to researchers developing this technology. A summary publication capturing the findings from the four African consultations was published in Malaria Journal in October 2019.

Problem Formulation for Gene Drive Mosquitoes Designed to Reduce Malaria Transmission in Africa: Results from Four Regional Consultations 2016–2018, Malaria Journal (2019).

Project Name:
Regional Consultations on Problem Formulation for Gene Drive Mosquitoes Designed to Reduce Malaria Transmission in Africa
Years:
2016-2019
Funding:
Foundation for the National Institutes of Health (FNIH), Bill and Melinda Gates Foundation
Partner:
New Partnership for Africa’s Development (NEPAD)
Geography:
Africa

Discover

Publications

Genetic Biocontrol for Invasive Species

Frontiers in Bioengineering and Biotechnology | May 25, 2020

This publication provides an overview of the state of genetic biocontrol, focusing on several approaches that were the subject of presentations at the Genetic Biocontrol for Invasive Species Workshop, which was sponsored by the OECD’s Co-operative Research Program on Biological Resource Management for Sustainable Agricultural Systems.

Problem Formulation for Gene Drive Mosquitoes Designed to Reduce Malaria Transmission in Africa: Results from Four Regional Consultations 2016–2018

Malaria Journal | October 15, 2019

This summary publication captures the findings from four African consultations organized by the New Partnership for Africa’s Development (NEPAD) to identify risk hypotheses and data needs for future environmental risk assessment of gene drives in the mosquito Anopheles gambiae.

OECD Consensus Document of the Biology of Mosquito Aedes aegypti

Safety Assessment of Transgenic Organisms in the Environment (Volume 8) | June 23, 2018

Volume 8 of the series Safety Assessment of Transgenic Organisms in the Environment contains the first OECD biosafety consensus document to deal with the biology of an insect, the mosquito Aedes aegypti.

Results from the Workshop “Problem Formulation for the Use of Gene Drive in Mosquitoes”

American Journal of Tropical Medicine and Hygiene | November 29, 2016

Reducing the incidence of malaria has been a public health priority for nearly a century. However, before new technologies and associated vector control strategies can be developed and exploited, it will be necessary to understand and assess the likelihood of any potential harms to humans or the environment. To begin this process, the Foundation for the National Institutes of Health and the Agriculture & Food Systems Institute organized an expert workshop to consider the potential risks related to the use of gene drives in Anopheles gambiae for malaria control in Africa.