553 - Safety and Immunogenicity of V114, a 15-Valent Pneumococcal Conjugate Vaccine, Followed by 23-Valent Pneumococcal Polysaccharide Vaccine in Children Living with HIV: A Phase 3 Trial (PNEU-WAY PED)

Poster Number: 553
Publication Number: 553.328

Marissa Wilck, Merck & Co., Inc., North Wales, PA, United States; Shaun L. Barnabas, Famcru, Stellenbosch University, Cape Town, Western Cape, South Africa; Kulkanya Chokephaibulkit, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok-noi, Krung Thep, Thailand; Svitlana Yesypenko, Odesa regional center of socially significant diseases, Odesa, Odes'ka Oblast', Ukraine; Elena V. Mikviman, Merck, Richboro, PA, United States; Leslie Morgan, Merck & Co, Inc, North Wales, PA, United States; Kristen A. Feemster, Merck & Co., Inc, North Wales, PA, United States; Joseph Chiarappa, Merck & Co. Inc., Doylestown, PA, United States; Luwy K. Musey, Merck & Co., Inc., North Wales, PA, United States

Background: HIV infection leads to immunity defects in children, increasing the risk of invasive pneumococcal disease (IPD). V114 is a 15-valent pneumococcal conjugate vaccine (PCV) that contains the 13 Streptococcus pneumoniae serotypes (STs) in 13-valent PCV (PCV13) plus two additional STs, 22F and 33F, which are important causes of IPD.

Objective: This multicenter, double-blind study (NCT03921424) evaluated the safety, tolerability, and immunogenicity of V114 in children 6–17 years of age living with HIV (CD4+ T-cell count ≥200 cells/μL, plasma HIV RNA < 50,000 copies/mL).

Design/Methods: Participants were randomized 1:1 to receive V114 (n=203) or PCV13 (n=204) on Day 1 followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23) at Week 8.

Results: Median age was 13 years, 52% were male, and 92% had CD4+ T-cell count ≥500 cells/μL. At 30 days post-PCV, ST-specific immunoglobulin G (IgG) geometric mean concentrations (GMCs) were generally comparable between V114 and PCV13 recipients for the 13 shared STs and higher with V114 compared with PCV13 for the two unique STs (22F and 33F) (primary immunogenicity endpoint) (Table); similar results were seen for ST-specific opsonophagocytic activity (OPA) geometric mean titers (GMTs). At 30 days post-PPSV23, IgG and OPA responses were generally comparable between V114 and PCV13 recipients for all 15 STs in V114. Following vaccination with PCV, 79% of participants in the V114 group and 70% in the PCV13 group reported ≥1 adverse event (AE); vaccine-related injection-site and systemic AEs were reported by 71% and 48% of participants in the V114 group, respectively, and by 60% and 38% of participants in the PCV13 group, respectively. The most frequently reported solicited AEs were injection-site pain and swelling, and myalgia; most solicited AEs were mild in intensity and of short duration (≤3 days). Following vaccination with PPSV23, the nature, frequency, intensity, and duration of solicited injection-site and systemic AEs were generally comparable in both vaccination groups. Six serious AEs occurred during the study (one post-V114, one post-PCV13, and two per group post-PPSV23); none were considered vaccine related.Conclusion(s): In children living with HIV, V114 was well tolerated and induced immune responses for all 15 pneumococcal STs. Sequential administration with PPSV23 8 weeks later was well tolerated and immune responses were maintained.
Table. IgG GMCs at 30 days post-vaccination with V114 or PCV13