Using CRISPR gene-editing technology, researchers have produced mosquitoes unable to replicate Zika virus and therefore also unable to infect a human through biting. In 2016, the World Health Organization called the Zika virus epidemic a “public health emergency of international concern” due to the virus causing birth defects for pregnant women in addition to neurological problems. Since then, researchers have wrestled with different strategies for controlling the spread of Zika virus, which gets transmitted to humans from female mosquito bites. One approach, which the Environmental Protection Agency approved in May, will release more than 750 million genetically modified mosquitoes into the Florida Keys in 2021 and 2022. These “suicide mosquitoes” are genetically-altered to produce offspring that die before emerging into adults and therefore cannot bite humans and spread disease.