Development of a fast release immunomodulated vaccine, against Foot and

QUATTROCCHI, V.;; LANGELLOTTI, C; PAPPALARDO, S; OLIVERA, V.; DI GIACOMO, S; MONGINI C; WALDNER C; ZAMORANO, P

Sicilia-Italia.

Congreso; 2008 Open Session of the The European Commission for the control of Foot-and-Mouth disease (EuFMD) Standing Technical Committee; 2008

The European Commission for the control of Foot-and-Mouth disease (EuFMD)

Introduction: Foot and Mouth Disease (FMD) is an acute disease caused by Foot and Mouth Disease Virus (FMDV). During an outbreak, the surrounding cattle must be ring vaccinated with an emergency vaccine.  In this research, we studied the early immune response and the protection induced by immunomodulated vaccines with inactivated FMDV. Materials and methods: animals (BALB/C mice or adult cattle) were immunized with experimental vaccines using inactivated FMDV (iFMDV) or formulated with inactivated virus plus adjuvant MONTANIDE ESSAI IMS D 12802 PR (802-iFMDV) (liquid with organic vegetal nanoparticles and an immunostimulating) or ISA206 (W/O/W) (206-iFMDV) (Seppic). The vaccines were non toxic using egg embryos. Protection against viral challenge was assessed. Results: At 4 and 7 dpv mice vaccinated with 802-iFMDV and 206-iFMDV, showed an increase of protection percentages compared to the iFMDV group. Both groups presented increased titters of FMDV-specific antibodies (Abs) compared to control. In vivo depletion of macrophages (but not the Natural Killer depletion) in vaccinated mice, severely decreased protection after virus challenge, indicating a central role of this population in the response elicited. Accordingly, in vitro, opsonization and phagocytes, were augmented in 802-iFMDV and 206-iFMDV vaccinated mice. Vaccination in cattle using the 802-iFMDV formulation, induced 100% of protection to the viral challenge at 4 and 7 dpv, compared to 33% obtained at 7 dpv by vaccine formulated only with iFMDV. Also, 802-iFMDV vaccinated cattle presented an increased number in the macrophage population as well as augmented levels of IFNgƒn in vitro production from peripheral blood mononuclear cells. Discussion: These results demonstrate the ability of these adjuvants to enhance the FMDV-specific protective response, and the important role of opsonization and antibody-mediated phagocytosis in vivo, in the early protective immune response against FMDV infection.