Inclusion Criteria:  Is in good health. Any underlying chronic illness must be documented to be in stable condition. Has received a 2-dose regimen of the Moderna mRNA SARS-CoV-2 vaccine ≥6 months before enrollment. A female participant is eligible to participate if she is not pregnant or breastfeeding, and at least one of the following conditions applies: Is not a woman of childbearing potential (WOCBP) OR Is a WOCBP and using an acceptable contraceptive method, or is abstinent from heterosexual intercourse.  Exclusion Criteria:  Has a current or known history of SARS-CoV-2 infection. Has a history of myocarditis and/or pericarditis. Has a known or suspected impairment of immunological function including, but not limited to, a history of congenital or acquired immunodeficiency, documented human immunodeficiency virus (HIV) infection, functional or anatomic asplenia, or history of autoimmune disease. Has a coagulation disorder contraindicating intramuscular vaccinations. Had a recent illness with fever (defined as oral or tympanic temperature ≥100.4°F [≥38.0°C]; axillary or temporal temperature ≥99.4°F [≥37.4°C]) or received antibiotic therapy for an acute illness occurring <72 hours before receipt of study vaccine. Has a known malignancy that is progressing or has required active treatment <3 years before enrollment. Received prior administration of a pneumococcal polysaccharide vaccine <5 years before study enrollment or is expected to receive a pneumococcal polysaccharide vaccine during the study outside the protocol. Received prior administration of a PCV <1 year before study enrollment or is expected to receive a PCV during the study outside the protocol. Received prior administration of any SARS-CoV-2 vaccine other than the 2-dose regimen of the Moderna mRNA vaccine, or is expected to receive any SARS-CoV-2 vaccine during the study outside the protocol. Received systemic corticosteroids for ≥14 consecutive days and has not completed intervention ≥30 days before study enrollment. Received systemic corticosteroids exceeding physiologic replacement doses ≤14 days before receipt of study vaccine. Is currently receiving immunosuppressive therapy, including chemotherapeutic agents used to treat cancer or other conditions, and interventions associated with organ or bone marrow transplantation, or autoimmune disease. Received any non-live vaccine ≤14 days before receipt of study vaccine or is scheduled to receive any non-live vaccine ≤30 days after receipt of study vaccine. Exception: Inactivated influenza vaccine allowed if given ≥7 days before or ≥15 days after receipt of study vaccine. Received any live virus vaccine ≤30 days before receipt of study vaccine or is scheduled to receive any live virus vaccine ≤30 days after receipt of study vaccine. Received a blood transfusion or blood products (including globulin) ≤6 months before receipt of study vaccine or is scheduled to receive a blood transfusion or blood product ≤30 days after receipt of study vaccine. Is currently participating in or has participated in an interventional clinical study with an investigational compound or device within 2 months of participating in this current study.