This.

For those that don't know, or have underdeveloped google skills, the flu (all forms) is viral, and malaria is a parasite.

Completely different deal.

The human immune system is fairly adept at fighting off viruses and bacteria. In either case, there is enough difference in the biochemistry that there are plenty of "targets" for medication to be effective without poisoning the host.

Parasites, especially multicellular parasites, the immune system is far less able to handle. Biochemically speaking, they are more similar to our own, so there are far less targets for medication to go after (IE you need something to make them sick, without making you sick).

Malaria especially has a really nasty habit of changing its protein profile after every "emergence", which makes is darn near impossible for your immune system to recognize, and makes creating any kind of vaccine fiendishly difficult.

Certainly you need the insect vector, but the end result is far worse.

Nu