PIRACICABA, Brazil — From its gleaming, year-old factory in this southeast Brazilian city, Oxitec, a British biotech firm, has built a thriving business releasing tens of millions of genetically engineered mosquitoes to protect populations from illnesses like dengue, chikungunya, and Zika.
But the company sees its future here not just in big factories but in a new business model centered on miniature labs, where mosquito eggs can be raised and released into neighborhoods. These mosquitoes carry a gene that causes their offspring to die before reaching maturity, with the goal of reducing vector-borne diseases.
Last November, Oxitec introduced its first “mobile production unit” in Juiz de Fora, an inland city of 500,000. Eggs from the Piracicaba factory are raised in mosquito hatcheries crammed inside the 40-foot rectangular lab that could pass for a white shipping container, condensing the work of a high-tech Silicon Valley-esque facility into just a single room.
In coming months, the company said, it hopes to finalize contracts with another handful of Brazilian cities, beginning with interventions that cover areas with as few as 10,000 residents.
“There are 5,000 municipalities [in Brazil] that have serious issues with chikungunya and dengue,” said Jorge Espanha, Oxitec’s general manager for Brazil. “We have to adapt our solution to our mobile production units.”
That’s a 180-degree turn for the company, which has spent the last half-decade scaling up its Piracicaba operation to support its biggest insect deployment in Brazil. Now, its focus has turned to scaling down its operation and replicating its Juiz de Fora experiment.
The company is betting that through this more diffuse strategy, it can move faster to scale up — or down — in locations where people are threatened by vector-born illnesses.
The modularity also helps with a quirk of the mosquito business: population interventions require larger numbers of mosquitoes at the beginning and fewer during what’s called the “maintenance stage,” which aims simply to keep newly reduced population sizes below natural levels. Mobile units have enough lab space to meet that need, the company hopes.
“If your demand decreases by 50 percent after the suppression phase,” said Karla Tepedino, the director of production and distribution for Oxitec in Brazil, “why would I build a huge factory that produces what I need in the suppression phase but when I’m in maintenance phase it produces more than that?”
Widespread use of the mobile units, Oxitec says, would make its product vastly more cost-effective for governments at all levels hoping to contract the firm for vector control. And a lower price point, Espanha said, could lead to a sea change in the way Brazil fights vector-borne illness.
Still, critics say, Oxitec’s mosquitoes haven’t been shown to work at a nationwide scale — and so if Brazil goes all-in for mobile labs, it may be a gamble.
Mosquito supply and demand
The manufacturing process for all of Oxitec’s mosquitoes in Brazil begins at the Piracicaba factory, a Silicon Valley-esque facility in layout and technology. The company’s roughly 130 Brazil-based employees share the space with rogue insects that hover over desks and land on cafeteria room lunch trays, where they’re routinely zapped with tennis racket-shaped electric swatters.
It’s there that scientists hatch billions of male Aedes aegypti mosquitoes over the course of a given year, each containing a self-limiting gene that causes their offspring to die before reaching maturity.
The ultimate goal is to drastically reduce mosquito populations and the diseases — including Zika, dengue, and chikungunya — that they spread. In the Cayman Islands, for instance, where Oxitec’s latest intervention began in 2016, mosquito populations fell by 62 percent.
Presently, the bugs are hatched, fed, sorted by sex, and transferred to distribution units from the Piracicaba facility. But it’s all those tasks that the company now hopes the trailer units can take on.
Oxitec, while declining to cite specific negotiations, says plans are in the works for another handful of cities in which it can begin deploying mobile units and attempting to control mosquito populations. And if cities decide to pull out of projects, scale up, or scale down, there’s been little waste.
“This is the other beauty of it,” said Tepedino. “If you decide to build a factory for any reason, you can just put those mobile units there while we’re building the facility.”
A cheaper solution?
And the cost argument is central to Oxitec’s pitch to prospective host communities.
An Oxitec-commissioned study released last month indicated that the 2 million cases of illnesses spread by Aedes aegypti mosquitoes in 2016 — namely dengue, chikungunya, and Zika — cost Brazil more than $730 million in economic productivity.
Oxitec says the mobile units could be a lower-cost way to combat that problem for cash-strapped countries and municipalities not capable of signing contracts that can fund factory-scale operations.
But some remain skeptical of Oxitec’s strategy, billed as a near-panacea for a country that has twice claimed to have wiped out its Aedes aegypti population only to see it return with a vengeance. Research in the field has accelerated quickly in recent years, and skepticism of such interventions is common among local populations and the science community alike.
“Results from epidemiological trials remain the primary missing information for assessment of the public health value of this product,” Dr. Haroldo Bezerra, a public health entomology and vector control adviser to the Pan American Health Organization, told STAT. “Epidemiological studies must be carried out to assess the public health value of reducing vector populations through the application of [Oxitec’s mosquitoes].”
From Oxitec’s perspective, things seem simpler: Brazil has tried before, notably in the 1940s and 1950s, to eradicate its Aedes aegypti population, only to see the insects make a resurgence.
To Espanha and Oxitec, that history indicates that a shift in Brazil’s vector-control approach is needed.
“They are already spending the money,” Espanha said, “but it seems that the solution is still not there.”