Safety and immunogenicity of a novel 10-valent pneumococcal conjugate vaccine candidate in adults, toddlers, and infants in The Gambia-Results of a phase 1/2 randomized, double-blinded, controlled trial

Vaccine. 2020 Jan 10;38(2):399-410. doi: 10.1016/j.vaccine.2019.08.072. Epub 2019 Dec 14.


Background: A more affordable pneumococcal conjugate vaccine (PCV) that provides comparable protection to current PCVs is needed to ensure sustainable access in resource-limited settings. Serum Institute of India Pvt. Ltd.'s PCV candidate (SIIPL-PCV) has the potential to meet this need as manufacturing efficiency has been optimized and the vaccine targets the most prevalent disease-causing serotypes in Africa and Asia. We report SIIPL-PCV's safety, tolerability, and immunogenicity in adults, toddlers, and infants in The Gambia.

Methods: This phase 1/2, randomized, double-blind trial sequentially enrolled 34 PCV-naive adults (18-40 years old), 112 PCV (Prevenar 13® [PCV13])-primed toddlers (12-15 months old), and 200 PCV-naive infants (6-8 weeks old), who were randomized (1:1) to receive SIIPL-PCV or a licensed comparator vaccine. Infants received three-doses of SIIPL-PCV or PCV13 at 6, 10, and 14 weeks of age co-administered with routine Expanded Program on Immunization (EPI) vaccines. Reactogenicity was solicited through seven-days post-vaccination; unsolicited adverse events (AEs) were assessed throughout the study. The safety and immunogenicity of a matching booster at 10-14 months of age were evaluated in a subset of 96 infants. Immune responses were evaluated post-primary and pre- and post-booster vaccinations.

Results: Reactogenicity was primarily mild-to-moderate in severity. In infants, the most common solicited reactions were injection-site tenderness and fever, with no meaningful treatment-group differences. There were no serious or severe vaccine-related AEs and no meaningful trends in SAEs, vaccine-related AEs, or overall AEs. Infant post-primary seroresponse rates (IgG level ≥ 0.35 µg/mL) were ≥89% for all serotypes except 6A (79%) in the SIIPL-PCV group. IgG GMCs were >1 µg/mL for all serotypes in both SIIPL-PCV and PCV13 groups. Post-booster GMCs were comparable between groups.

Conclusion: SIIPL-PCV was well-tolerated, had an acceptable safety profile, and was immunogenic for all vaccine serotypes. Results support the evaluation of SIIPL-PCV in a phase 3 non-inferiority trial. NCT02308540.

Keywords: Adult; Immunogenicity; Infant; Phase 1/2; Pneumococcal conjugate vaccine; Reactogenicity; Safety; Toddler; Tolerability.

Publication types

  • Clinical Trial, Phase I
  • Clinical Trial, Phase II
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Double-Blind Method
  • Female
  • Gambia
  • Humans
  • Immunization Programs
  • Immunization Schedule
  • Immunization, Secondary / methods*
  • Infant
  • Male
  • Pneumococcal Infections / immunology
  • Pneumococcal Infections / prevention & control*
  • Pneumococcal Vaccines / administration & dosage*
  • Pneumococcal Vaccines / adverse effects
  • Pneumococcal Vaccines / immunology
  • Vaccination*
  • Young Adult


  • 10-valent pneumococcal conjugate vaccine
  • Pneumococcal Vaccines

Associated data