I saw this on The Horse.com; a vaccine for sweet itch is in the works. I'm not too enthusiastic about vaccinations, but having had some horses with this condition, it would definitely be of interest. Also interesting that it is such a world wide problem, that researchers are working on a solution.
https://thehorse.com/160153/novel-ibh-vaccine-for-horses-tested/
https://thehorse.com/160153/novel-ibh-vaccine-for-horses-tested/