Problems posed by potential gonococcal vaccines viewed from the vantage point of a control agency.

Progress in the characterisation of Neisseria gonorrhoeae and other bacterial pathogens has suggested that immunoprophylaxis for gonorrhoea may be possible despite the well-known propensity for reinfection. Pili, outer membrane proteins, a capsular polysaccharide, and the lipopolysaccharide may be important gonococcal virulence factors, and immune components (probably antibodies) to more than one of these antigens may be required to confer immunity. A study of antigenic polymorphism of these structures should identify disease isolates more precisely and provide information about the relationship between variants of these gonococcal structures and gonococcal virulence.