FDA gives preliminary go-ahead for Florida release of genetically engineered mosquitoes

This morning the U.S. Food and Drug Administration published a notice that a field trial of genetically engineered mosquitoes in the Florida Keys would not harm humans or the environment. The preliminary ‘finding of no significant impact’, which is subject to a 30-day public comment period, will effectively allow the Florida Keys Mosquito Control District to release mosquitoes developed by British biotech firm Oxitec into the environment.


Dr. Zachary Adelman, Associate Professor, Department of Entomology, Virginia Tech (webpage):

Expertise: Molecular and genetic interactions between arboviruses and their mosquito hosts; molecular biology and genetic manipulation of the vector mosquito, Aedes aegypti.

“I’m glad to see that cooler heads have prevailed, and that this trial looks like it will be allowed to go forward. Although it remains to be determined whether suppression the female Ae. aegypti population through the use of Oxitec mosquitoes will result in meaningful epidemiological outcomes, the preliminary finding of no significant environmental impact is consistent with what has been observed following these releases in other parts of the world. By allowing the trial, the FDA will be signaling that science and evidence-based practices should prevail over the hysteria and irrationality long associated with genetically-modified organisms.”


Dr. David O’Brochta, Professor, Department of Entomology, University of Maryland (webpage):

Expertise: genetic technologies for use in insects and the application of those technologies to explore the physiology and genetics that make some mosquitoes excellent vectors of human pathogens.

“Oxitec’s general approach to developing a control strategy for reducing populations of Aedes aegypti using genetics is well documented as is their specific technology in this case, OX513A mosquitoes*.  I am not surprised by a finding of no significant impact by the FDA for their proposed field trial in Florida.

“A male OX513A mosquito released by Oxitec is essentially a flying non-chemical ‘insecticide’ that seeks out and targets Aedes aegypti females and their offspring.   These mosquitoes do not persist in the environment and all mosquitoes with Oxitec’s mosquito-killing gene die.  High specificity, high efficacy and no persistence in the environment is more than can be said about the current approaches used to control Aedes aegypti in Florida, which involve fairly non-specific chemicals that have a measurable environmental footprint.”


Dr. Jason Rasgon, Associate Professor of Disease Epidemiology, Penn State University (webpage):

Expertise: Vector arthropods and the pathogens they transmit, with emphasis on release of genetically-modified mosquitoes for disease control, pathogen transmission dynamics and bioterrorism issues.

I’m not surprised that the FDA has published a finding of no significant impact. As far as controlling Aedes aegypti goes, releasing the Oxitec mosquitoes is a good idea because it’s safe and the chance of something going wrong is pretty negligible. It’s definitely got a lower environmental footprint than spraying insecticides all over the place and has good chance of controlling Aedes aegypti. I’m a fairly big supporter of the technology which has been proven to work in a number of countries already. Of all the GM or GM-like strategies for mosquito control that are being talked about I think it’s by far the safest and the least likely to have off target effects.”


Dr. Bruce Hay, Professor of Biology, California Institute of Technology (webpage): 

Expertise: Developmental biology and genetics, including developing transgenic mosquitoes that lack the ability to transmit pathogens such as malaria, dengue fever and chikungunya.

This is a welcome and timely decision by the FDA. Dengue, chikungunya and Zika are all dangerous viruses transmitted by the Aedes aegypti mosquito, an invasive species that has no business being in North or South America at all. The FDA’s evaluation of data and information from Oxitec and others was rigorous and complete. In short, there is no biologically plausible mechanism by which the release of these male mosquitoes could do anything other than what it is intended to do, which is to decrease the population of the wild Aedes aegypti mosquito population.”


Dr. Thomas Scott, Distinguished Professor of Entomology and Epidemiology, University of California, Davis (webpage):

Expertise: The ecology, epidemiology, and prevention of vector-borne disease.

The announcement from FDA regarding finding of no significant impact for Oxitec mosquitoes is a significant regulatory accomplishment for the company.  Assuming that conclusion continues to be supported after the public comment period, trials in the Florida Keys will generate additional valuable information for assessing the public health and cost effectiveness of their mosquito strain.”



Declared interests (see GENeS register of interests policy):

Dr. Zachary Adelman: “I have no association with Oxitec, Intrexon, or any of the scientists doing the work, nor have I at any point in the development of the technology. I am working on developing technology that might eventually compete with Oxitec, but that is a long way away.”

Dr. David O’Brochta: “I have no affiliation with Oxitec or Intrexon and have no conflicts of interest in this case.”

Dr. Thomas Scott: “I collaborated with Oxitec in a research project that studied a different genetically modified strain of Aedes aeypti than OX513A. Our collaboration ended during 2013. I serve on the Vector Control Advisory Group (VCAG) for the World Health Organization (WHO), which serves as an advisory body to WHO on new forms of vector control for malaria and other vector-borne diseases. Oxitec submitted an application to VCAG during the time that I was on the committee.”

No further interests declared.



FDA announcement:



*Dr. O’Brochta’s comment initially said Oxitec’s Environmental Assessment is not yet publicly available. It is in fact available at the above page on the FDA website.

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