Streptococcal Infections

The purpose of this study is to assess the safety of 3 doses of 2 new Strep A vaccine formulations, one with an Alum adjuvant, and the other with AS37 adjuvant. The Strep A vaccine will be tested for the first time in humans, in healthy young adults 18 to 25 years of age. The study will also assess if the vaccines have any immediate reactions and if they induce an immune response. A low, medium, and high dose of each formulation of the vaccine will be assessed in sequence.

This clinical study will enroll 100 participants from the 2-month-old (minimum 6 weeks) group who previously participated in the Phase III clinical trial of the 13-valent pneumococcal polysaccharide conjugate vaccine (CRM197, TT vector) (Protocol No.: CS-CTP-PCV), with 50 participants in each of the treatment and control groups, and who have completed blood sample collection for the 1-year and 2-year immunogenicity studies. All participants will have 3.0-3.5 mL of venous blood collected for the immunogenicity study.

Streptococcal anginosus infections (S. constellatus, S. anginosus, and S. intermedius) are characterized by their severity, linked to high mortality and frequent infectious complications. Several studies in the literature highlight this severity, with mortality rates estimated at around 15%. The aim of this research is to identify the factors associated with mortality in Streptococcal anginosus bacteremia.