Scientists have developed a mosquito that spreads vaccine instead of disease. The researchers, led by molecular geneticist Shigeto Yoshida of Jichi Medical University in Tochigi Japan, transformed mosquitoes into vaccine-carrying syringes by genetically engineering the insects to express the vaccine for leishmaniasis – a parasitic disease transmitted by the sandfly – in their saliva. According to their article in Insect Molecular Biology, mice bitten by these mosquitoes produced antibodies against the parasite. "Following bites, protective immune responses are induced, just like a conventional vaccination but with no pain and no cost," said lead researcher Shigeto Yoshida in a press release from the journal. "What's more continuous exposure to bites will maintain high levels of protective immunity, through natural boosting, for a life time. So the insect shifts from being a pest to being beneficial." It's still unclear whether the immune response was strong enough to protect against infection. The project is considered more of a proof of principle experiment than a viable public health option, at least for now. Via Techreview, via ScienceNow.