A Phase 2 Study Evaluating the Safety and Efficacy of Whole-Cell Pneumococcal Vaccine (wSp) in Reducing Nasopharyngeal Colonization by Streptococcus Pneumoniae in Young Children.
The goal of this clinical trial is to evaluate whether the wSp vaccine can prevent nasopharyngeal colonization by pneumococcal bacteria in healthy young children who have received routine PCV20 vaccination. The main questions it aims to answer are: Does wSp vaccine reduce pneumococcal colonization in the nose? Does wSp vaccine safely stimulate the immune system to produce antibodies and protective immune responses? Researchers will compare children receiving two injections of wSp vaccine to those receiving saline placebo to see if wSp vaccine reduces colonization and boosts immunity. Participants will: Receive two injections of either wSp or saline at 7 and 9 months of age. Have blood samples taken at 6 and 12 months to measure immune responses. Have nasal swabs collected at several time points and during infections from 6-24 months. Be monitored for ear infections, respiratory illnesses, and other pneumococcal-related infections.
• Male or female who is 6 months (+/- 30 days) of age at time of enrollment
• Healthy subject as established by medical history and clinical examination before entering into the study.
• Received 3 doses of PCV-20.
• Written informed consent obtained from the subject's parent/legal guardian.
• Parent/legal guardian able and willing to bring subject to all study visits.