Researchers say for the first time an entire city, Townsville in northern Queensland, has been protected from the viral disease dengue fever.
Captive-bred mosquitoes with a naturally occurring bacteria were released, where they mated with local mosquitoes. By spreading a bacteria which hinders dengue transmission, the city has been dengue-free since 2014.
Researchers from Monash University also believe their work could stop mosquito-borne diseases Zika and malaria.
"Nothing we've got is slowing these diseases down - they are getting worse," said Scott O'Neill, director of the World Mosquito Program.