Diseases are a potentially threat to humanity. Despite their disappearance from the news they are still out there.

Recent developments in vaccines and methods of vaccine production point toward the possibility of universal vaccines for both flu and HIV, vaccines that might protect against most, if not all, forms of the disease, and methods of production that are far faster and cheaper. It is offering hope that we some day might be able to eliminate both flue and HIV as we have eliminated smallpox.

http://scienceblogs.com/grrlscientist/2010/06/tedtalks_seth_berkley_hiv_and.php

Being somewhat of a cynic I would ask this question - what vaccine company would be dumb enough to develop a vaccine that would eliminate the need for future vaccines?

I doubt that that is a realistic fear in the foreseeable future. An example might be polio. The disease itself is still around. Places that haven't seen a polio case in decades are all just a flight or two away from someplace where it is still hanging around.

Smallpox was possible to eliminate in part because there are no known animal hosts. HIV has primate hosts. Which is where we might have got it from originally. Flu is endemic to birds and swine. We might eliminate the risk of HIV and flu but not the diseases themselves. For the foreseeable future, assuming a vaccine were successfully created, a vaccine would still mean everyone at risk needs to be vaccinated, and there are always boosters. This would be similar to how tetanus is handled.