npj Vaccines (Sep 2022)

Safety and immune response kinetics of GRAd-COV2 vaccine: phase 1 clinical trial results

  • Chiara Agrati,
  • Concetta Castilletti,
  • Simone Battella,
  • Eleonora Cimini,
  • Giulia Matusali,
  • Andrea Sommella,
  • Alessandra Sacchi,
  • Francesca Colavita,
  • Alessandra M. Contino,
  • Veronica Bordoni,
  • Silvia Meschi,
  • Giulia Gramigna,
  • Federica Barra,
  • Germana Grassi,
  • Licia Bordi,
  • Daniele Lapa,
  • Stefania Notari,
  • Rita Casetti,
  • Aurora Bettini,
  • Massimo Francalancia,
  • Federica Ciufoli,
  • Alessandra Vergori,
  • Serena Vita,
  • Michela Gentile,
  • Angelo Raggioli,
  • Maria M. Plazzi,
  • Antonella Bacchieri,
  • Emanuele Nicastri,
  • Andrea Antinori,
  • Stefano Milleri,
  • Simone Lanini,
  • Stefano Colloca,
  • Enrico Girardi,
  • Roberto Camerini,
  • Giuseppe Ippolito,
  • Francesco Vaia,
  • Antonella Folgori,
  • Stefania Capone

DOI
https://doi.org/10.1038/s41541-022-00531-8
Journal volume & issue
Vol. 7, no. 1
pp. 1 – 11

Abstract

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Abstract Despite the successful deployment of efficacious vaccines and therapeutics, the development of novel vaccines for SARS-CoV-2 remains a major goal to increase vaccine doses availability and accessibility for lower income setting. We report here on the kinetics of Spike-specific humoral and T-cell response in young and old volunteers over 6 months follow-up after a single intramuscular administration of GRAd-COV2, a gorilla adenoviral vector-based vaccine candidate currently in phase-2 of clinical development. At all three tested vaccine dosages, Spike binding and neutralizing antibodies were induced and substantially maintained up to 3 months, to then contract at 6 months. Potent T-cell responses were readily induced and sustained throughout the study period, with only minor decline. No major differences in immune response to GRAd-COV2 vaccination were observed in the two age cohorts. In light of its favorable safety and immunogenicity, GRAd-COV2 is a valuable candidate for further clinical development and potential addition to the COVID-19 vaccine toolbox to help fighting SARS-CoV-2 pandemic.