Sarker P, Mily A, Ara A, Haque F, Maier N, Wierzba TF, Walker RI, Venkatesan MM, Raqib R. Functional antibodies and innate immune responses to WRSS1, a live oral Shigella sonnei vaccine candidate in Bangladeshi adults and children.
J Infect Dis 2021;
224:S829-S839. [PMID:
34374425 PMCID:
PMC8687094 DOI:
10.1093/infdis/jiab395]
[Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Background
We demonstrated in a randomized placebo-controlled trial that WRSS1, a live oral Shigella sonnei vaccine candidate, is safe in Bangladeshi adults and children, and elicits antigen-specific antibodies. Here, we describe functional antibody and innate immune responses to WRSS1.
Methods
Adults (18–39 years) and children (5–9 years) received 3 doses of 3 × 105 or 3 × 106 colony forming units (CFU) of WRSS1 or placebo, 4 weeks apart; children additionally received 3 × 104 CFU. Blood and stool were collected at baseline and 7 days after each dose. Functional antibodies were measured using serum bactericidal antibody (SBA) assay. Cytokine/chemokine concentrations were measured in lymphocyte cultures. Host defense peptides LL-37, HBD-1, and HD-5 were analyzed in plasma and stool.
Results
Children showed increased SBA titers over baseline after the third dose of 3 × 106 CFU (P = .048). Significant increases of Th-17 and proinflammatory cytokines (TNF-α, G-CSF, MIP-1β), and reduction of anti-inflammatory and Th2 cytokines (IL-10, IL-13, GM-CSF) were observed in children. Plasma HBD-1 and LL-37 decreased in children after vaccination but were increased/unchanged in adults.
Conclusions
Functional antibodies and Th1/Th17 cytokine responses in children may serve as important indicators of immunogenicity and protective potential of WRSS1.
Clinical Trials Registration: NCT01813071.
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