Accelerating the development of a group A Streptococcus vaccine: an urgent public health need.

Group A Streptococcus (GAS) infections cause substantial worldwide morbidity and mortality, mostly associated with suppurative complications such as pharyngitis, impetigo, and non-suppurative immune syndromes such as acute rheumatic fever, rheumatic heart disease, and acute post-streptococcal glomerulonephritis. Deaths occur mostly in children, adolescents, and young adults in particular pregnant women in low- and middle-income countries. GAS strains are highly variable, and a GAS vaccine would need to overcome the issue of multiple strains. Several approaches have been used multivalent vaccines using N-terminal polypeptides of different M protein; conserved M protein vaccines with antigens from the conserved C-repeat portion of the M protein; incorporation selected T- and B-cell epitopes from the C-repeat region in a synthetic polypeptide or shorter single minimal B-cell epitopes from this same region; and non-M protein approaches utilizing highly conserved motives of streptococcal C5a peptidase, GAS carbohydrate and streptococcal fibronectin-binding proteins. A GAS vaccine represents urgent need for this neglected disease and should therefore deserve the greatest attention of international organizations, donors, and vaccine manufacturers.