Safety and Immunogenicity of 20vPnC in Toddlers With 2 Prior Doses of Prevenar 13

A PHASE 3, RANDOMIZED, PARTIALLY DOUBLE-BLIND TRIAL TO EVALUATE THE SAFETY AND IMMUNOGENICITY OF 20-VALENT PNEUMOCOCCAL CONJUGATE VACCINE IN HEALTHY TODDLERS 12 THROUGH 23 MONTHS OF AGE WITH 2 PRIOR INFANT DOSES OF PREVENAR 13

The purpose of this study is to understand the safety and effects of a study vaccine (20vPnC) in toddlers who had 2 prior doses of Prevnar 13.

This study is being conducted in children who:

• are between 12 to 23 months of age;
• are healthy as determined by the study doctors;
• have received 2 doses of Prevnar 13 during the first year in life.

Participants in this study will receive either 1 dose or 2 doses of the study vaccine or 1 dose of Prevnar 13 as a shot in the muscle. During the study, participants will have to come to the study clinic to receive the vaccines and have blood sample collected. The study team will work with participants' parents or legal guardians to monitor any unwanted reactions to the vaccines. Participants are expected to take part in this study for about 1 or 3 months, for 1 dose or 2 dose schedules, respectively.

Inclusion Criteria:

• Male or female toddlers ≥12 to <24 months of age at the time of consent
• Healthy toddlers determined by clinical assessment, including medical history and clinical judgment, to be eligible for the study
• 2 infant doses of Prevenar 13 prior to 12 months of age

Exclusion Criteria:

• History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis)
• Major known congenital malformation or serious chronic disorder
• Other chronic medical or laboratory abnormality that may increase the risk associated with study participation or, in the investigator's judgment, make the participant inappropriate for the study.
• Previous vaccination with any investigational pneumococcal vaccine, or planned receipt through study participation