A Study to Evaluate Tolerability, Safety and Immunogenicity of MVX01 Pneumococcal Vaccine

The study will enroll five cohorts. Ascending doses of MVX01 will be evaluated in cohorts 1-4, in participants 18-50 years of age. The highest tolerated dose from cohorts 1-4 will be evaluated in cohort 5, in participants 60-75 years of age. Cohort 1 will be open-label. Cohorts 2-5 will enroll two open-label sentinel participants followed by the remainder of the cohort which will be randomized and double-blind. Each participant will be administered two doses of study intervention via intramuscular injection, approximately 1 month apart. Immunogenicity will be evaluated up to approximately 6 months following administration of the second dose.