While NIH Argues with Congress for Zika Funding, FDA Gives Green-Light to Investigational Release of Genetically Engineered Mosquitos

By Jay W. Cormier –

It is no surprise that in a presidential election year that every piece of legislation in Washington gets an extra dose of political theater. Federal funding for Zika virus research is no exception.  The President and the NIH have been asking Congress for months to provide additional resources to support research designed to learn more about the virus and to develop vaccines to prevent wide-spread infection.

With all the attention that the 2016 Summer Olympics has brought to concerns about Zika virus, it is somehow fitting that last Friday, just hours before the opening ceremonies in Rio, FDA’s Center for Veterinary Medicine (CVM), in consultation with the U.S. Environmental Protection Agency’s Office of Pesticide Programs Biopesticides and Pollution Prevention Division, the Centers for Disease Control and Prevention’s Division of Vector-Borne Diseases, and the National Institutes of Health National Institute of Allergy and Infectious Diseases’ Laboratory of Malaria and Vector Research, issued a final Environmental Assessment (EA) and Finding of No Significant Impact (FONSI) regarding a proposed investigational release of genetically engineered (GE) mosquitos.

The mosquitos, being developed by Oxitec Ltd. (Oxitec), have a specific genetic change that is lethal to offspring when they are not exposed to a specific antibiotic, tetracycline. The mosquitos, of the species Aedes aegypti, are the specific type of mosquitos that have been at the center of the recent Zika virus infections in Miami, and are also known to transmit dengue, chikungunya, and yellow fever.  Continuing the linkage with Rio, earlier this year Oxitec reported that field trials of their mosquitos in Brazil resulted in a 96% drop in the wild mosquito population in the trial area in just 6 months.  Oxitec hopes to have similar results in field trials in Key Haven, Florida – just east of Key West.  In the Florida study, Oxitec will evaluate: (1) the ability of released Oxitec mosquitoes to mate with local wild-type Ae. aegypti females; (2) the survival of the resultant progeny in order to estimate mortality related to inheritance of the recombinant DNA (rDNA) construct; and (3) the efficacy of sustained releases of the Oxitec mosquitoes for the suppression of a local population of Ae. aegypti in the defined release area.

When FDA approved GE Atlantic salmon for commercial production and introduction into the human food supply in 2015 (see our post on that approval here), FDA issued an EA and FONSI, as required by the National Environmental Policy Act (NEPA).  What is unique with FDA’s decision last week is that CVM has elected to publicly issue an EA and FONSI for the investigational use of the GE mosquitos.  FDA concluded its EA stating that “data and information presented and evaluated indicates that the investigational use of [the Oxitec] mosquitoes, as described in th[e] EA, would not result in significant effects on the quality of the human environment.”

To be clear, don’t go throwing out your DEET just yet.  Even if the Florida field trial is successful, Oxitec will still need to seek full FDA approval for the mosquitos via a New Animal Drug Application (NADA), which will include issuing another draft EA that will consider the effects on the human environment of wide-spread release of the mosquitos.