Why did my hayfever abruptly disappear?
I've been suffering from hayfever ever since I was in junior high school, but suddenly two years ago when I was in university, it was seemingly cured. I've never had any medication or anything like that. What happened?
Presumably his immune system just got the hang of dealing with that pollen. Instead of making IgE antibodies against it, it presumably changed to making IgG. The other type of development in the immune system is when another type of cell comes along called the T-regulatory cell. That is allergen-specific but gives off cytokines, the communication chemicals that damp down the immune system. So whereas there used to be an allergic reaction, it may be that his T-regulatory cells have now got the hang of controlling that and that's great news for him.