Gonococcal vaccines.

The quest for a vaccine against Neisseria gonorrhoeae has been long, arduous, and, to date, unsuccessful. Indeed, some experts, citing the recurrent nature of gonococcal infections in some people, have believed the task to be impossible (2). However, there has been at least one human challenge study that has demonstrated protection against the homologous infecting organism after immunization with purified gonococcal pili (4). Furthermore, N. gonorrhoeae is quite antigenic for humans, local and systemic immune responses have been demonstrated against virtually every gonococcal antigen studied, and relative resistance to infection has been correlated with a history of previous infections (22).