Vaccine. 2017 May 2;35(19):2531-2542. doi: 10.1016/j.vaccine.2017.03.071. Epub 2017 Apr 4.
Odutola A1, Ota MO2, Antonio M3, Ogundare EO4, Saidu Y5, Foster-Nyarko E6, Owiafe PK7, Ceesay F8, Worwui A9, Idoko OT10, Owolabi O11, Bojang A12, Jarju S13, Drammeh I14, Kampmann B15, Greenwood BM16, Alderson M17, Traskine M18, Devos N19, Schoonbroodt S20, Swinnen K21, Verlant V22, Dobbelaere K23, Borys D24.
Conserved pneumococcal proteins are potential candidates for inclusion in vaccines against pneumococcal diseases. In the first part of a two-part study, an investigational vaccine (PHiD-CV/dPly/PhtD-30) containing 10 pneumococcal serotype-specific polysaccharide conjugates (10VT) combined with pneumolysin toxoid and pneumococcal histidine triad protein D (30μg each) was well tolerated by Gambian children. Part two, presented here, assessed the efficacy of two PHiD-CV/dPly/PhtD formulations against pneumococcal nasopharyngeal carriage (NPC) prevalence in infants.
In this phase 2, randomized, controlled, observer-blind trial, healthy infants aged 8-10weeks, recruited from a peri-urban health center, were randomized (1:1:1:1:1:1) into six groups. Four groups received PHiD-CV/dPly/PhtD (10 or 30μg of each protein), PHiD-CV, or 13-valent pneumococcal conjugate vaccine at ages 2-3-4months (3+0 infant schedule) and two groups PHiD-CV/dPly/PhtD-30 or PHiD-CV at 2-4-9months (2+1 infant schedule). The primary objective was impact on non-10VT NPC at ages 5-9-12months. Secondary objectives included confirmatory analysis of protein dose superiority and safety/reactogenicity. Impact on pneumococcal NPC acquisition, bacterial load, and ply and phtD gene sequencing were explored.
1200 infants were enrolled between June 2011 and May 2012. Prevalences of pneumococcal (60-67%) and non-10VT (55-61%) NPC were high at baseline. Across all post-vaccination time points, efficacy of PHiD-CV/dPly/PhtD-10 and PHiD-CV/dPly/PhtD-30 against non-10VT NPC (3+0 schedule) was 1.1% (95% CI -21.5, 19.5) and 2.1% (-20.3, 20.3), respectively; efficacy of PHiD-CV/dPly/PhtD-30 (2+1 schedule) was 0.5% (-22.1, 18.9) versus PHiD-CV. No differences were observed in pneumococcal NPC acquisition, clearance, or bacterial load. Both protein-based vaccines elicited immune responses to pneumococcal proteins.
In this high carriage prevalence setting, inclusion of pneumococcal proteins in the PHiD-CV/dPly/PhtD investigational vaccine had no impact on pneumococcal NPC in infants, regardless of protein dose or schedule. Future evaluations will assess its impact against pneumococcal disease endpoints.
PATH, GlaxoSmithKline Biologicals SA. ClinicalTrials.gov identifier NCT01262872.
Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
Infant; Nasopharyngeal carriage; Pneumococcal histidine triad protein D; Pneumolysin; Streptococcus pneumoniae; Vaccine efficacy
PMID: 28389097 DOI: 10.1016/j.vaccine.2017.03.071