The American floulbrood vaccine is a traditional one based on inactivated bacteria not a GMO vaccine.

The Florida Keys trial released genetically modified male mosquitoes, as the males don't bite. These mate with the invasive species of mosquitoes in Florida that transmit disease and this makes sure that their female larvae don't make it to the biting stage.

> Aedes aegypti makes up about 4% of the mosquito population in the Keys, a chain of tropical islands off the southern tip of Florida. But it is responsible for practically all mosquito-borne disease transmitted to humans in the region, according to the Florida Keys Mosquito Control District (FKMCD), which is working closely with Oxitec on the project. Researchers and technicians working on the project will release bioengineered male Aedes aegypti mosquitoes, which don’t bite, to mate with the wild female population, responsible for biting prey and transmitting disease. The genetically engineered males carry a gene that passes to their offspring and kills female progeny in early larval stages. Male offspring won’t die but instead will become carriers of the gene and pass it to future generations. As more females die, the Aedes aegypti population should dwindle.

https://www.nature.com/articles/d41586-021-01186-6