Immunogenicity of a 2 + 1 Infant Vaccination Series with 13-Valent Pneumococcal Conjugate Vaccine (PCV13) Followed by Pneumococcal Non-Typeable Haemophilus influenzae Protein D Conjugate Vaccine (PHiD-CV): a Randomized Trial Exploring Interchangeability of PCVs

• Published in: Open forum infectious diseases 2017-10, Vol.4 (suppl_1), p.S538-S539
• Main Authors: Santos, Abiel Mascareñas De Los, Rodríguez-Weber, Miguel Angel, Sánchez-Márquez, Pedro, Carreño-Manjarrez, Roberto, Cervantes-Apolinar, María Yolanda, Ruiz-Guiñazú, Javier, Ortega-Barria, Eduardo, Borys, Dorota
• Format: Article
• Language: English
• ISSN: 2328-8957; 2328-8957
• DOI: 10.1093/ofid/ofx163.1402

Abstract Background Data on the immunogenicity of PHiD-CV after 1 or more doses of PCV13 during infant vaccination may provide useful information for countries considering a switch between or sequential use of these vaccines in their immunization programs. We assessed their interchangeability in a 2 + 1 infant schedule, starting with PCV13 (1 or 2 doses) and continuing with PHiD-CV. Methods In this phase III, partially blind, multicenter study (NCT01641133) in Mexico, infants were randomized 1:1:1 to receive 2-dose primary vaccination and a booster (at 2, 4 and 12–15 months of age) with either PHiD-CV (SSS control group), or PCV13 at priming and PHiD-CV at booster (PPS group) or PCV13 followed by PHiD-CV at priming and PHiD-CV at booster (PSS group). Immunogenicity was measured pre- and 1 month post-priming, and pre- and 1 month post-booster by ELISA. Results for the safety objectives were presented before. Results The according-to-protocol cohorts for immunogenicity at primary and booster vaccination comprised 260 and 258 children, respectively. In children who received 2 primary PCV13 doses and a PHiD-CV booster (PPS), for each serotype common to both PCVs (except 9V), post-booster immune responses were in similar ranges to those after a 2 + 1 PHiD-CV series (SSS) (Figure 1B). In children who received 1 PCV13 dose followed by 2 PHiD-CV doses (PSS), for most common serotypes, the percentages of children with pneumococcal antibody concentrations ≥0.2 µg/mL were in similar ranges post-priming and post-booster compared with SSS controls (Figure 1). For some serotypes, post-primary (5, 6B, 9V, 23F) and post-booster (4, 5, 6B, 7F, 9V, 23F) antibody GMCs tended to be lower in the PSS than in the SSS group. Protein D carrier antibody GMCs were higher in the SSS group (post-pri: 2025.1 ELU/mL; post-bst: 3658.5 ELU/mL) than in the PPS (143.2 and 219.7 ELU/mL) and PSS (117.2 and 791.0 ELU/mL) groups. Conclusion A 2 + 1 series with 2 PCV13 primary doses followed by a PHiD-CV booster or 1 PCV13 dose followed by a PHiD-CV primary and booster dose elicited pneumococcal immune responses in line with those induced by a 2 + 1 series with PHiD-CV alone, albeit with a trend for lower antibody GMCs for some serotypes. The clinical relevance of this trend is unknown. Funding. GlaxoSmithKline Biologicals SA Disclosures R. Carreño-Manjarrez, GSK: Employee and Shareholder, Salary; M. Y. Cervantes-Apolinar, GSK: Employee and Shareholder, Salary; J. Ruiz-Guiñazú, GSK: Employee and