When I was an FDA official, the agency’s lawyers laid down a basic principle: “When public health is at stake, do what you need to, and we’ll find a legal justification. We have plenty of legal tools.” I found that to be true. For example, in order to get a dangerous product withdrawn from commerce quickly, there is the “imminent hazard” provision in the FDA’s regulations that may be invoked when a product or practice poses “a significant threat of danger to health” that “should be corrected immediately to prevent injury.”
Conversely, the FDA can authorize the emergency use of an unapproved product in a situation that poses a public-health emergency, such as an emerging disease, for example a new strain of pandemic influenza. There is a detailed protocol to follow for the FDA to issue an Emergency Use Authorization of Medical Products, which begins with the secretary of HHS (or of defense or of homeland security) declaring that a significant health emergency exists.
Does the Zika outbreak qualify? There is a good argument that it does. There have been more than 16,000 cases of Zika infection in U.S. territories (most in Puerto Rico) and scores of locally acquired cases in Florida. The number of locally transmitted cases is continuing to increase, as are the known modes of transmission. Zika infection is known to cause severe birth defects early in pregnancy and subtler ones later. It can also cause a progressive paralysis called Guillain-Barré syndrome. At the direction of the governor, Florida’s surgeon general has declared a public-health emergency for 29 counties in the state.
Vaccines are years — probably many years — away from commercialization, so control of the mosquito carriers is the most promising short-term approach. One such approach uses molecular genetic-engineering techniques to create male Aedes aegypti mosquitoes with a mutation that makes them need a certain chemical (the antibiotic tetracycline) to survive. Without it, they die — as do their offspring — before reaching maturity. If these males are fed a diet containing tetracycline (to keep them alive long enough to reproduce) and then released into the wild over several months, the result is a marked reduction in the mosquito population. Because male mosquitoes don’t bite, they present no health risk, and because their progeny die before they can reproduce, no genetically engineered mosquitoes persist in the environment. (Moreover, Aedes aegypti is an invasive species in the Americas, so there’s no possibility that reducing their numbers will disrupt natural ecosystems.)
This approach has already been successfully tested abroad. Efficacy trials of the genetically engineered mosquitoes in Malaysia, Brazil, Panama, and the Cayman Islands all resulted in greater than 90 percent suppression of the wild population of Aedes aegypti mosquitoes.
But U.S. regulators were unwilling to permit even small-scale field testing during a five-year review of the application, which they finally approved last month. (The proposed single field trial will be in the Florida Keys, 160 miles from the Zika outbreak in Miami.)
The genetically engineered mosquitoes should really be regulated by the USDA’s Animal and Plant Health Inspection Service, which has the authority and expertise to oversee field trials and commercialization of genetically engineered insects. (In fact, the technique of using sterile insects to control pest populations was developed at the USDA in the 1940s, but for a combination of reasons, including budgetary concerns and antagonism to genetic engineering among some senior USDA officials, the department demurred and ceded oversight to the FDA.)
Another, somewhat similar approach is to release male Aedes aegypti mosquitoes that have been infected with a certain strain of the bacterium Wolbachia; the infected males mate with females in the wild, but early studies have shown that many of the eggs don’t hatch. This method is being field-tested in California’s Central Valley. Infection with other strains of Wolbachia makes the mosquitoes less competent vectors. For reasons that make sense only to bureaucrats, Wolbachia-infected mosquitoes are regulated more leniently by the EPA under its pesticide statute. The spraying of chemical insecticides has not been highly effective in controlling Aedes aegypti (although it has decimated beneficial insects, including honeybees).
#share#So how do we address the public-health threat from the mosquitoes that carry the Zika virus? The EPA can grant pesticide emergency exemptions for unapproved pesticides — such as the Wolbachia-infected mosquitoes — “when a serious pest problem jeopardizes production of agricultural goods or public health but no pesticides are currently registered for that situation.” These exemptions are for “a limited use of the pesticide in specific geographic areas for a finite period of time.”
For its part, the FDA should return regulatory jurisdiction over the genetically engineered Aedes aegypti to the USDA — but it has been unwilling to do so. Alternatively, the FDA could issue an emergency use authorization (EUA) for widespread use of genetically engineered mosquitoes in areas prone to Zika infections. Pursuant to HHS Secretary Sylvia Burwell’s determination in February that there is “a significant potential for a public health emergency,” the FDA has issued ten EUAs for tests to diagnose active or past Zika infections and could do so for other regulated products as well. However, according to the Tampa Bay Times, “the FDA has previously said that its rules prohibit the emergency use of animal products,” including this “animal drug.” That reflects the FDA’s callousness and irresponsibility more than the constraints of law and regulation.
As long as four statutory criteria have been met — the presence of a serious or life-threatening disease, a “may be effective” standard for effectiveness, a risk-benefit analysis, and the absence of alternatives — the FDA does have the authority. But, illustrating the condescension and unhelpfulness of the FDA, an agency spokeswoman suggested that Florida political leaders eager to see the genetically engineered mosquitoes used in their jurisdictions should contact Oxitec, the manufacturer, directly to get them to request permission from the FDA for a field trial — via the same regulatory mechanism that took five years to approve the trial in the Florida Keys!
#related#In government, personnel choices are policy choices. The Obama administration’s appointments have been execrable, and in the microcosm of the Zika virus debacle, we are seeing the results. None of the officials who could intervene to solve urgent problems — senior White House officials, including the president’s science advisor; the head of the Domestic Policy Council; the U.S. surgeon general; and the involved agency heads — have stepped up.
Whether federal officials, from the trenches at the FDA to the White House, will finally do their jobs and follow through on these possibilities expeditiously remains to be seen. I’m not optimistic.
— Henry I. Miller, a physician and molecular biologist, is the Robert Wesson Fellow in Scientific Philosophy and Public Policy at Stanford University’s Hoover Institution. He was the founding director of the FDA’s Office of Biotechnology.