Study of a Pneumococcal Conjugate Vaccine in Adults Aged 50 to 84 Years.

Inclusion criteria : \- Aged 50 to 84 years on the day of inclusion . Exclusion criteria: * Participant was pregnant, or lactating, or of childbearing potential and was not using an effective method of contraception or abstinence from at least 4 weeks prior to vaccination until at least 4 weeks after vaccination. To be considered of non-childbearing potential, the female must have been post-menopausal for at least 1 year, or surgically sterile. * Participation at the time of the study enrollment (or in the 4 weeks preceding the trial vaccination) or planned participation during the present trial period in another clinical trial investigating a vaccine, drug, medical device or medical procedure. * Received any vaccine in the 4 weeks preceding the trial vaccination or planned receipt of any vaccine from enrollment through the last blood sampling Visit, except for influenza vaccination, which may be received at least 2 weeks before study vaccine. This exception includes monovalent pandemic influenza vaccines and multivalent influenza vaccines. * Previous vaccination against S. pneumoniae with either a pneumococcal conjugated vaccine (PCV) or a pneumococcal polysaccharide vaccine (PPSV). * Received immune globulins, blood or blood-derived products in the past 3 months. * Known or suspected congenital or acquired immunodeficiency, or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within the preceding 6 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months). * History of S. pneumoniae infection or disease, confirmed either serologically, or microbiologically. * History of Guillain-Barré syndrome occurring within 6 weeks after a prior dose of a TTxd-containing vaccine. * Experienced an Arthus-type hypersensitivity reaction following a prior dose of a TTxd-containing vaccine \< 10 years ago. * Known systemic hypersensitivity to any of the vaccine components, or history of a life threatening reaction to the vaccines used in the trial or to a vaccine containing any of the same substances . * Verbal report of thrombocytopenia contraindicating IM vaccination in the Investigator's opinion. * Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating IM vaccination in the Investigator's opinion. * At risk of invasive pneumococcal disease (eg, participants with functional or anatomic asplenia, participants with severe asthma, participants travelling to countries with high endemicity). * Current alcohol abuse or drug addiction. * Chronic illness that, in the opinion of the Investigator, is at a stage where it might interfere with trial conduct or completion. * Any condition that in the opinion of the Investigator could interfere with the evaluation of the vaccine (eg, under investigation or monitoring for possible coronavirus disease 2019 \[COVID-19\]). * Moderate or severe acute illness/infection (according to investigator judgment) on the day of vaccination or febrile illness (temperature ≥ 100.4 F). A prospective participant should not be included in the study until the condition has resolved or until 3 days after the febrile event has subsided. * Received oral or injectable antibiotic therapy within 72 hours prior to the first blood draw. * Identified as an Investigator or employee of the Investigator or study center with direct involvement in the proposed study, or identified as an immediate family member (ie, parent, spouse, natural or adopted child) of the Investigator or employee with direct involvement in the proposed study. The above information was not intended to contain all considerations relevant to a participant's potential participation in a clinical trial.