Anti-Streptococcal Vaccine

Anti-Streptococcal Vaccine

Anti-Streptococcal Vaccine: Search for an effective anti streptococcal vaccine has been going on for decades. Still there is no vaccine which has been approved for human use!
It is well known that school children are more affected by streptococcal infections than adults. This is because adults acquire some protection due to repeated infections in childhood and accumulation of protective antibodies against type specific regions of M protein or conserved M epitopes. Conserved antigens are antigens shared by most or all serotypes.

M-protein cross-reacts with myocardium and hence an M-protein based vaccine for prevention of rheumatic fever may not be safe. It may trigger an autoimmune response and lead to exactly the same disease it is meant to prevent – acute rheumatic fever with carditis! M-protein is strain-specific and strains vary from place to place.

Mutations can occur in weeks, making the Anti-Streptococcal Vaccine ineffective. Hence an effective anti streptococcal vaccine for prevention of rheumatic fever is difficult to develop.

Another obstacle is that rheumatic fever occurs mainly in the under privileged world. Hence it may be difficult to recover the huge cost of vaccine development even if one is developed!

Reference

1. Dale JB, Batzloff MR, Cleary PP, Courtney HS, Good MF, Grandi G, Halperin S, Margarit IY, McNeil S, Pandey M, Smeesters PR, Steer AC. Current Approaches to Group A Streptococcal Vaccine Development.  In: Ferretti JJ, Stevens DL, Fischetti VA, editors. Streptococcus pyogenes : Basic Biology to Clinical Manifestations [Internet]. Oklahoma City (OK): University of Oklahoma Health Sciences Center; 2016 Feb 10.