"It will probably not be possible to eradicate all infectious disease. The current bacterial population of Earth may be ~1031 organisms and so the chances are good that most of them are going to survive in some host reservoir, somewhere on the planet, for as long as life exists here, despite our best efforts to eradicate them. However, it should be possible to eliminate all harmful effects, and all harmful natural disease organisms, from the human body, allowing us to lead lives that are free of pathogen-mediated illness (at least most of the time). A simple antimicrobial nanorobot like the microbivore should be able to eliminate even the most severe bloodborne infections in treatment times on the order of an hour; more sophisticated devices could be used to tackle more difficult infection scenarios."
January 1, 1970
https://en.wikiquote.org/wiki/Nanotechnology