Frontiers in Immunology (Sep 2022)

Whole-cell vaccine candidates induce a protective response against virulent Acinetobacter baumannii

  • Stephen J. Dollery,
  • Daniel V. Zurawski,
  • Ruth V. Bushnell,
  • John K. Tobin,
  • Taralyn J. Wiggins,
  • David A. MacLeod,
  • Naomi J. P. E. R. Tasker,
  • Yonas A. Alamneh,
  • Rania Abu-Taleb,
  • Christine M. Czintos,
  • Wanwen Su,
  • Mariel G. Escatte,
  • Heather N. Meeks,
  • Michael J. Daly,
  • Gregory J. Tobin

DOI
https://doi.org/10.3389/fimmu.2022.941010
Journal volume & issue
Vol. 13

Abstract

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Acinetobacter baumannii causes multi-system diseases in both nosocomial settings and a pre-disposed general population. The bacterium is not only desiccation-resistant but also notoriously resistant to multiple antibiotics and drugs of last resort including carbapenem, colistin, and sulbactam. The World Health Organization has categorized carbapenem-resistant A. baumannii at the top of its critical pathogen list in a bid to direct urgent countermeasure development. Several early-stage vaccines have shown a range of efficacies in healthy mice, but no vaccine candidates have advanced into clinical trials. Herein, we report our findings that both an ionizing γ-radiation-inactivated and a non-ionizing ultraviolet C-inactivated whole-cell vaccine candidate protects neutropenic mice from pulmonary challenge with virulent AB5075, a particularly pathogenic isolate. In addition, we demonstrate that a humoral response is sufficient for this protection via the passive immunization of neutropenic mice.

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