Vaccine-related major cutaneous reaction size correlates with cellular-mediated immune responses after tularaemia immunisation.

Abstract

OBJECTIVES:

Francisella tularensis, the causative agent of tularaemia, is an exceptionally infectious bacterium, potentially fatal for humans if left untreated and with the potential to be developed as a bioweapon. Both natural infection and live-attenuated vaccine strain (LVS) confer good protection against tularaemia. LVS vaccination is traditionally administered by scarification, and the formation of a cutaneous reaction or take at the vaccination site is recognised as a clinical correlate of protection. Although previous studies have suggested that high antibody titres following vaccination might serve as a useful surrogate marker, the immunological correlates of protection remain unknown.

METHODS:

We investigated the host T-cell-mediated immune (T-CMI) responses elicited following immunisation with LVS vaccine formulated by the DynPort Vaccine Company (DVC-LVS) or the United States Army Medical Research Institute of Infectious Diseases (USAMRIID-LVS). We compared T-CMI responses prompted by these vaccines and correlated them with take size.

RESULTS:

We found that both LVS vaccines elicited similar T-CMI responses. Interestingly, take size associated with the T cells' ability to proliferate, secrete IFN-γ and mobilise degranulation, suggesting that these responses play an essential role in tularaemia protection.

CONCLUSIONS:

These results renew the appreciation for vaccination through the scarification as a prime route of inoculation to target pathogens driving specific T-CMI responses and provide further evidence that T-CMI plays a role in protection from tularaemia.

• Authors: Rosangela Salerno-Gonçalves, Wilbur H Chen, Mark J Mulligan, Sharon E Frey, Jack T Stapleton, Wendy A Keitel, Jason Bailey, Eli Sendra, Heather Hill, Robert A Johnson, Marcelo B Sztein
• Journal: Clinical & translational immunology (Clin Transl Immunology) Vol. 10 Issue 1 Pg. e1239 ( 2021) ISSN: 2050-0068 [Print] Australia
• PMID: 33505681 (Publication Type: Journal Article)
• Copyright: © 2021 The Authors. Clinical & Translational Immunology published by John Wiley & Sons Australia, Ltd on behalf of Australian and New Zealand Society for Immunology, Inc.