No reason why there isn't a vaccine for every bacterial STD. I've often wondered why there isn't. Is it the governments idea of punishing immoral people?
Originally Posted by John Bull
There are some challenges plus cost/benefit analysis.
Standard vaccine technology of the sort developed by Pasteur depends on the reality that a person, once exposed to a pathogen, develops an immunological memory of that pathogen that boosts immune response for later exposures.
Some STDs simply do not do that. Unlike smallpox or chicken pox where, once you get it you will never get it again due to immunological memory; many STDs such as gonorrhea leave no such memory. Therefore, you are just as vulnerable to subsequent infections as you were to the first.
Vaccines in the Pasteur method work by exposing the immune system to a dead or attenuated version of the pathogen; of which immunological memory is retained, for later application when the real thing comes along.
A substantial amount of research has gone into creating vaccines for gonorrhea, chlamydia and syphillis; but with all three curable by antibiotics the matter isn't as pressing as with viral STDs that can't be cured such as HSV-2, HPV and HIV.
With syphillis, creation of a vaccine, though theoretically possible, has proven challenging due to the nature of the surface proteins. Animal trials have been abysmal.
A chlamydia vaccine is in the works with a company in Australia and looks promising.
A gonorrhea vaccine has so far shown no promise due to failure of the body to form an immunological memory.
All of these are ultimately surmountable; but, as I mentioned, the priority is a bit lower than with incurable diseases.
I'm not a big fan of government; but I don't think they conspired in this case. :-)