Prospects for a group A streptococcal vaccine.

Group A streptococcal (GAS) infections are associated with a number of human diseases, including pharyngitis, impetigo, necrotizing fasciitis, streptococcal toxic shock syndrome and rheumatic heart disease. An increase in the incidence of severe GAS infections in Western countries, and the awareness of the burden of GAS-associated diseases in developing nations, which remains high in spite of the availability of antibiotics, has provided the impetus for development of a safe and efficacious GAS vaccine. This has focused on the M protein, a major GAS virulence factor, however, with the publication of several GAS genomes, a number of non-M vaccine candidates are now under investigation.