Have a read up on the use of hookworms as a suppressant for hayfever and other immune system overreactions. It seems like there's more work to be done there, a

Have a read up on the use of hookworms as a suppressant for hayfever and other immune system overreactions. It seems like there's more work to be done there, and lots of potentially exaggerated stories of big pharma trying to shut research down, but the hypothesis has always sounded sensible to me, and what little formal research I've heard of has been extremely positive.