Putative correlates of protection against shigellosis assessing immunomarkers across responses to S. sonnei investigational vaccine

Autor: Valentino Conti, Omar Rossi, Kristen A. Clarkson, Francesca Mancini, Usman N. Nakakana, Eleanna Sarakinou, Andrea Callegaro, Pietro Ferruzzi, Alessandra Acquaviva, Ashwani Kumar Arora, Elisa Marchetti, Francesca Necchi, Robert W. Frenck, Laura B. Martin, Robert W. Kaminski, Audino Podda, Francesca Micoli
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: npj Vaccines, Vol 9, Iss 1, Pp 1-10 (2024)
Druh dokumentu: article
ISSN: 2059-0105
DOI: 10.1038/s41541-024-00822-2
Popis: Abstract Shigella spp. are a leading bacterial cause of diarrhea. No widely licensed vaccines are available and there is no generally accepted correlate of protection. We tested a S. sonnei Generalized Modules for Membrane Antigen (GMMA)-based vaccine (1790GAHB) in a phase 2b, placebo-controlled, randomized, controlled human infection model study (NCT03527173) enrolling healthy United States adults aged 18–50 years. We report analyses evaluating immune responses to vaccination, with the aim to identify correlates of risk for shigellosis among assessed immunomarkers. We found that 1790GAHB elicited S. sonnei lipopolysaccharide specific α4β7+ immunoglobulin (Ig) G and IgA secreting B cells which are likely homing to the gut, indicating the ability to induce a mucosal in addition to a systemic response, despite parenteral delivery. We were unable to establish or confirm threshold levels that predict vaccine efficacy facilitating the evaluation of vaccine candidates. However, serum anti-lipopolysaccharide IgG and bactericidal activity were identified as potential correlates of risk for shigellosis.
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