Evaluation of the Potency, Neutralizing Antibody Response, and Stability of a Recombinant Fusion Protein Vaccine for Streptococcus pyogenes.

Streptococcus pyogenes or group A streptococcus (GAS) is a Gram-positive bacterium that can cause a wide range of diseases, including pharyngitis, impetigo, scarlet fever, necrotizing fasciitis, rheumatic fever, and streptococcal toxic shock syndrome. Despite the increasing burden on global health caused by GAS, there is currently no licensed vaccine available. In this study, we evaluated immunogenicity, induction of neutralizing antibodies, and stability of a new recombinant fusion protein vaccine that targets infections from GAS. The recombinant fusion protein (SpeAB) combines inactive mutant forms of streptococcal pyrogenic exotoxin A (SpeA) and streptococcal pyrogenic exotoxin B (SpeB). The SpeAB vaccine evaluated in this study was adsorbed to an aluminum adjuvant and demonstrated robust immunogenicity, eliciting production of specific neutralizing antibodies against SpeA and SpeB, two major virulence factors of S. pyogenes. Stability studies suggest that the vaccine will retain immunogenicity for at least 2 years when stored at refrigerated temperatures. This novel vaccine shows great potential to provide protection against GAS infections and to reduce the burden of GAS disease globally.

[Seal of composite resin fillings]. / Etanchéité des obturations aux résines composites.

The daily use of composite resins, the rapid evolution in their composition and that of adhesives, as well as the defects in their dimensional stability on setting, led us to carry out this study on the sealing ability of modern bonded aesthetic fillings by measurement of the thickness of the dentine-filling hiatus. In vitro, category V dental fillings are made then sectioned, polished, dyed and observed under optic microscopy. Penetration of the dyeing agent unto the outer two-thirds of the fillings proves the lack of tightness. Enamel-composite limits are almost always acceptable. The dentine-composite hiatus measures between 4 and 8 micrometers on average with the use of new adhesives (from 1 to 10 micrometers maximum). This represents a substantial improvement in comparison to the old generation of adhesives which allowed hiatuses of 10 to 50 micrometers to show. No particular product of the new generation showed to be better in this study.