Establishment and characterization of a Wolbachia (wAlbB)-infected Aedes aegypti line (Tw-Kao) for dengue control

Global trade and climate change are driving the geographic expansion of dengue vectors, contributing to the global spread of dengue. Conventional vector control measures have proven insufficient to prevent substantial disease burdens, highlighting the need for innovative and sustainable strategies. The release of Wolbachia-infected mosquitoes offers a promising alternative for dengue suppression. Here, we developed a locally derived Ae. aegypti line carrying the wAlbB strain (wAlbB-Tw-Kao) and systematically evaluated its fitness, viral interference, and potential for vector population control. The strain was generated through embryonic microinjection of cytoplasm containing the intact wAlbB endosymbiont from field-collected Ae. albopictus in Kaohsiung, Taiwan, resulting in a stably infected mosquito line with 100% maternal transmission. Whole-genome sequencing confirmed a high similarity to the reference wAlbB genome. Cross-mating experiments demonstrated complete cytoplasmic incompatibility (CI, 0% egg hatch) when wAlbB-Tw-Kao males were mated with uninfected females. Antiviral assays against dengue virus serotype 2 (DENV-2) and Zika virus showed significant reductions in viral titers in the midgut, salivary glands, and saliva. In cage experiments, increasing release ratios of wAlbB-Tw-Kao males led to significant suppression of wild-type populations, achieving up to approximately 90% reduction in egg hatch. These findings demonstrate the successful development of a locally derived wAlbB-infected Ae. aegypti line with strong CI, stable maternal transmission, and effective DENV and ZIKV blocking. These properties provide a foundation for future field-relevant evaluation under both suppression and replacement deployment frameworks.