And there is research aplenty into treating and reducing malaria, including improving antimalarials, reducing the ability of the local mosquito populations to carry the oocysts and sporozoites, and arresting the stages in human liver and blood cells. It's just not being done by for profit pharma companies. That's why we need to be funding things like the CDC and supporting private foundations like the Gates Foundation.
I believe that far into the future, the Gates Foundation (along with a few other private health initiatives) will be remembered for saving countless lives and reducing untold morbidity.
We have evidence that malaria can be eradicated from previously-endemic areas, along with yellow fever, dengue and a few other dangerous diseases just by using very old low-tech approaches. What are your chances of catching dengue in Houston, yellow fever in New Orleans, or malaria in Charleston these days? Right - essentially zero. Those diseases used to be endemic in parts of the US. Merely because a country is more tropical or poorer doesn't mean similar approaches can't work there. Add more modern tools and there is no reason to think these diseases can't be eradicated altogether. It will just cost a very great deal and currently it's mostly poor people that contract those illnesses. Back to the original topic, DDT accounts for much of why you're not likely to catch malaria anywhere in the US.
Vaccination eradicated smallpox and rinderpest from the earth and measles from North America. We could without doubt eradicate measles altogether, along with poliomyelitis and a few other infectious diseases that respond well to vaccination if the will and the funding were there. It takes a lot of will and a lot of funding, and both of those are lacking.
Some infectious diseases change too rapidly or have too many hosts or vectors to be eradicable by current means. There is a significant list of very serious diseases that are unquestionably eradicable with current technology. The bill would be vastly lower than the world spends on war, but it's really hard to get people to stop warring with each other.