A Study to Learn About the Safety and Immune Response of a New Pneumococcal Vaccine in Adults

Inclusion Criteria: * Male or female participants ≥18 to\<50 years of age (Stage 1) and ≥50 years of age (Stage 2, Stage 3, and Stage 4) at the time of consent * Adults determined by clinical assessment to be eligible for the study, including adults with preexisting stable disease within 12 weeks before receipt of study intervention * Participants willing to use acceptable contraception for at least 28 days after study intervention; female participants not of childbearing potential; male participants unable to father children * Phase 1 (Stage 1): Adults 18 through 49 years of age with no history of ever receiving a pneumococcal vaccine (ie, pneumococcal vaccine-naïve) * Phase 2 (Stages 2, 3, and 4): Adults ≥50 through 64 years of age with no history of ever receiving a pneumococcal vaccine (ie, pneumococcal vaccine-naïve) and adults 65 years of age and older with either no history of ever receiving a pneumococcal vaccine or who received PPSV23 \>5 years prior to the first vaccination in this study (ie, experienced) Exclusion Criteria: * History of severe adverse reaction associated with a vaccine and/or severe allergic reaction to any component in pneumococcal conjugate vaccines and any other diphtheria toxoid-containing vaccine * Serious chronic disorder that in the investigator's opinion would make the participant inappropriate for entry into the study * Medical or psychiatric condition (recent or active suicidal ideation/behavior or laboratory abnormality) that may increase risk of study participation or make participant inappropriate for the study * Known or suspected immunodeficiency or other conditions associated with immunosuppression * Planned receipt of any licensed or investigational pneumococcal vaccine, or planned receipt of any licensed or investigational pneumococcal vaccine through study participation * Receipt of any inactivated or otherwise nonlive vaccine within 14 days or any live vaccine within 28 days before administration of study intervention