Overview

This is a Phase 2 clinical study to support the use of AFX3772 in healthy infants for the prevention of pneumococcal disease. The purpose of this study is to determine the safety, tolerability, and immunogenicity of 3 different dose levels of AFX3772 compared with PCV13. Infants approximately 2 months of age will be enrolled and receive 4 doses of study vaccine over 8 protocol-defined visits spanning a duration of approximately 18 to 21 months. Part 1 is the dose escalation, lead-in portion of the study in which infants at each dose level will be randomized 3:1 in sequential cohorts of increasing doses of AFX3772 or PCV13. Enrollment in Cohorts 2 and 3 will proceed following Data Monitoring Committee (DMC) review of cumulative safety and tolerability data from preceding cohorts. Following completion of DMC review of safety and tolerability data for the cohorts enrolled in Part 1, additional infants will be enrolled and randomized equally to receive either PCV13 or AFX3772 at different dose levels approved for evaluation in Part 2.

Eligibility

Inclusion Criteria:

• Is a full-term infant approximately 2 months of age at time of obtaining the informed consent.

Exclusion Criteria:

• Had prior administration of any pneumococcal vaccine.
• Has a known or suspected hypersensitivity to AFX3772, PCV13 or any components of the formulations used.
• Has a known or suspected immunodeficiency or other conditions associated with immunosuppression that may require immunosuppressive drugs. In addition, the participant's biological mother has known HIV infection or known to be hepatitis B surface antigen positive.
• Has any clinically significant allergic condition or history prior to the first vaccination for primary immunization series.
• Has a history of microbiologically proven invasive disease caused by S. pneumoniae.
• Has received immunoglobulins.
• Has a bleeding diathesis or condition associated with prolonged bleeding that would contraindicate intramuscular injection.
• Has received systemic corticosteroids for a period of more than 14 days and has not completed the treatment for at least 30 days before study vaccine.
• Has febrile illness at Visit 1.