Efficacy of a novel, protein-based pneumococcal vaccine against nasopharyngeal carriage of Streptococcus pneumoniae in infants: A phase 2, randomized, controlled, observer-blind study

•Pneumococcal protein antigens could provide serotype-independent protection.•Two PHiD-CV/dPly/PhtD vaccine formulations were assessed in healthy infants.•Both protein-based vaccines elicited immune responses to pneumococcal proteins.•The vaccines had no impact on pneumococcal nasopharyngeal carriage prevalence.•Future evaluations will assess their impact against pneumococcal disease endpoints.