I think the problem is that the protein is an anti-coagulant, which is necessary for mosquito's feeding strategy but is also something you probably want your bo

I think the problem is that the protein is an anti-coagulant, which is necessary for mosquito's feeding strategy but is also something you probably want your body to have a pretty robust reaction to and break down/expel pretty aggressively, lest each bite just keep bleeding well after the mosquito finishes feeding. Would for sure be nice if the immune response could skip the itching part though.