Here’s a study to file under “unworkable but very cool.” A group of Japanese researchers has developed a mosquito that spreads vaccine instead of disease. Even the researchers admit, however, that regulatory and ethical problems will prevent the critters from ever taking wing — at least for the delivery of human vaccines.

Scientists have dreamed up various ways to tinker with insects’ DNA to fight disease. One option is to create strains of mosquitoes that are resistant to infections with parasites or viruses, or that are unable to pass the pathogens on to humans. These would somehow have to replace the natural, disease-bearing mosquitoes, which is a tall order. Another strategy closer to becoming reality is to release transgenic mosquitoes that, when they mate with wild-type counterparts, don’t produce viable…

Fast-spreading parasite species force sex changes on their victims, induce virgin births, and turn animals into “gross monsters” — among other horrors. Now a new study has decoded how the bacteria may be able to wreak their havoc: by shutting down immune systems.

The parasites, of the Wolbachia bacteria genus, cause a gene in wasps to stifle the insect’s protein-based “alarms” against the bacterial invaders, say researchers who mapped the genomes of three species of Nasonia wasp for the first time. As a result, the wasps’ antibacterial defenses are never deployed, allowing Wolbachia to begin their dirty work.