Moving forward: a mucosal vaccine against group A streptococcus

Abstract

Streptococcus pyogenes, commonly referred to as group A streptococcus (GAS), colonizes the epithelial surfaces of the upper respiratory tract and the skin, where it causes a myriad of diseases that vary in clinical presentation and severity. Several candidate GAS vaccines are now approaching or have entered human clinical trials. However, the preclinical evaluation for the leading vaccine candidates has been premised on their ability to induce systemic protection through parenteral immunization. While systemic immunity has proven effective in preventing GAS dissemination and associated disease, it may not prove to be the optimal approach for inducing mucosal immunity against GAS. With this in mind, many researchers are moving toward testing the efficacy of their GAS vaccine candidate when delivered to the mucosal surface. This review discusses the interaction of GAS with the mucosal immune system and the approaches taken thus far in developing a mucosal GAS vaccine.