By CHIMPREPORTS
Dr. Florence Banoba
In response to the recent opinion article ‘Genetically modified mosquitoes a dangerous gamble’ , I wish to address the writer’s broad-brush dismissal of the significance of genetic modification technologies in combating malaria. It is crucial, from the outset, to clarify a fundamental distinction overlooked in the article between Gene-drive and Self-limiting technologies in addressing this global health challenge.
As rightly stated in that article, gene-drive technology refers to a genetic engineering technique that aims to spread a particular gene throughout a population at an accelerated rate. The primary objective would be to either suppress a mosquito population or reduce its ability to transmit malaria. Under this method, the introduced mosquitoes are designed to stay in the environment for long.
In contrast, self-limiting technology involves the introduction of genetically modified organisms which possess traits designed to limit their population growth. This technology focuses on controlling or suppressing the modified organisms themselves. Various mechanisms can be employed to achieve this, such as introduction of genes that cause sterility in offsprings, or genes that make the organisms dependent on specific external factors.
The article is silent on this second technology and yet, going by information available on their website, it appears the British firm, Oxitec, in partnership with Uganda Viral Research Institute, are exploring the use of the self-limiting technology to combat the threat of malaria, which infects millions of people every year in Uganda alone. Self-limiting mosquitoes have been widely deployed and are now fully approved for deployment in Brazil whilst gene drive technologies are at earlier stages of development.
Now comes the question of the efficacy of genetic modification technologies in the fight against malaria. Does genetic modification technology fare better than chemical control? In the article, the writer asserts that, “there is no evidence or proof that genetically modified mosquitoes would contribute to tackling the current challenges in the fight against malaria.” In the world of science, evidence is key.
Effective mosquito control-like destruction of breeding areas and indoor spraying as commonly used in Uganda-is widely recognized as a vitally important pillar in the fight against malaria and other mosquito-borne diseases. Genetically modified, self-limiting mosquitoes are proven as highly effective in reducing disease-spreading mosquitoes. In urban communities in Brazil, self-limiting mosquitoes have reduced the dengue mosquito, Aedes aegypti, by more than 90% in multiple pilot releases. These outcomes are reported and publicly accessible in peer-reviewed scientific publications. Similar solutions are under development for malaria-spreading mosquitoes, opening up the possibility of reduced reliance on chemical interventions, including development of a self-limiting anopheles mosquito solution to combat a highly invasive species responsible for the recent surge of malaria cases in Djibouti and the Horn of Africa.
Safety of the technology is another concern raised by the article. Is it accurate to assert that “…genetic engineering technique’s potential ecological and health impacts cannot be adequately assessed without first deploying it.”?
With rigorous scientific scrutiny, it is possible to assess a given technology’s impacts. This is what regulatory agencies do, all the time, when assessing new products for testing and commercialization. This includes genetically engineered organisms.
Regulatory agencies are well-equipped to assess new technologies, and self-limiting genetically engineered mosquitoes have received multiple approvals on the basis of their safety. As an example, Oxitec’s self-limiting mosquitoes have been the subject of multiple regulatory assessments of many thousands of pages of detailed scientific data describing their safety. In Brazil, the company’s solution for the dengue-spreading Aedes aegypti has been assessed as safe for people and the environment, and is now fully approved and serving communities nationwide. In the USA, the same self-limiting mosquitoes have been approved for pilots in the Florida Keys following detailed scientific review, with the Environmental Protection Agency (the EPA) issuing a finding that the pilots would not cause harm to humans or the environment.
With more than 1 billion self-limiting (non-biting) male mosquitoes deployed to date, there has been no report of negative impacts to people and the environment.
Independent review of new technologies is important. Policy makers and regulatory agencies in different countries frequently share research information about novel solutions to diseases to ensure anything introduced to the public is safe and up to standard. The Uganda Virus Research Institute conducts rigorous tests in-country on new medications, vaccines and technologies to ensure their efficacy and safety to avoid placing the public at risk of adverse effects.
The historical and recent global gains made in the fight against malaria, which has included malaria elimination in some countries, must be celebrated. However, as the World Health Organization’s World Malaria Report stated in late 2023, progress is stalling and malaria is again on the rise-at alarming rates in some countries. Uganda ranks 3rd highest in malaria cases worldwide. In terms of both malaria cases and deaths, the world is worse-off now than before the COVID pandemic. This is partly due to mosquitoes developing resistance to existing tools – they’re fighting back. As experts across Africa keep warning, relying on the status quo will not be enough to defeat this disease and new options are needed to regain ground.
New methods should be explored! Inaction and complacency in the fight against malaria will have their own consequences, and to assume that repeating the same strategies will turn the tide is analogous to burying one’s head in the sand. The global community needs to embrace innovation and provide better support to us on the malaria front line, who are running out of options and constantly running against the clock to save a child under 5years from dying or an expectant mother from losing her unborn child.
In the words of Dr Matshidiso Moeti, the World Health Organisation’s Regional Director for Africa, “To forge ahead toward a malaria-free future, we need a concerted effort to tackle these diverse threats that fosters innovation, resource mobilization and collaborative strategies.”
The writer is a Medical Doctor and Medicolegal/Policy consultant.
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