A phase 3, multicenter, randomized, double-blind study to evaluate the interchangeability of V114, a 15-valent pneumococcal conjugate vaccine, and PCV13 with respect to safety, tolerability, and immunogenicity in healthy infants (PNEU-DIRECTION)

Background: Pneumococcal disease (PD) remains a major health concern globally. In children, pneumo-coccal conjugate vaccines (PCVs) provide protection against PD from most vaccine serotypes, but non -vaccine serotypes contribute to residual disease. V114 is a 15-valent PCV containing all 13 serotypes in Prevnar 13TM (PCV13) and public health important serotypes 22F and 33F. This phase 3 study evaluated safety and immunogenicity of mixed PCV13/V114 regimens using a 3 + 1 dosing schedule when changing from PCV13 to V114 at doses 2, 3, or 4.Methods: 900 healthy infants were randomized equally to 5 intervention groups. PCVs were adminis-tered in a 3-dose infant series at 2, 4, and 6 months of age followed by a toddler dose at 12-15 months along with concomitant routine vaccines. Safety was evaluated as the proportion of participants with adverse events (AEs). Immunoglobulin G (IgG) responses to the 15 serotypes in V114 were measured at 30 days post-dose 3 and 30 days post-dose 4 (PD4). Results: Frequencies of injection-site and systemic AEs were generally comparable across all intervention groups. At 30 days PD4 (primary endpoint), IgG geometric mean concentrations (GMCs) for the 13 shared serotypes were generally comparable between mixed V114/PCV13 and 4-dose regimens of PCV13 or V114. In mixed regimens at 30 days PD4, a toddler dose of V114 was sufficient to achieve IgG GMCs com-parable to a 4-dose regimen of V114 for serotype 22F, while at least one infant dose was needed in addi-tion to the toddler dose to achieve IgG GMCs comparable to a 4-dose regimen of V114 for serotype 33F.Conclusions: V114 was well tolerated with a generally comparable safety profile to PCV13. For 13 shared serotypes, both mixed regimens and the V114 4-dose regimen induced generally comparable antibody responses to 4-dose regimen with PCV13. Study results support interchangeability of V114 with PCV13 in infants.Trial registration: ClinicalTrials.gov: NCT03620162; EudraCT: 2018-001151-12.(c) 2022 Published by Elsevier Ltd.