Vet. Res. 38 (2007) 1-14
DOI: 10.1051/vetres:2006040

Immunostimulatory properties of a novel adjuvant administered with inactivated influenza virus vaccine

Vincent Wellemans, Sylvette Laurent, Pierre Hélie and Youssef ElAzhary

Faculté de médecine vétérinaire, Université de Montréal, PO Box 5000, Saint-Hyacinthe, Qc, J2S 7C6, Canada

(Received 27 November 2005; accepted 12 June 2006; published online 1 November 2006)

Abstract - The immunopotentiating activity of a new delivery system was investigated comparatively to Alhydrogel adjuvant, as an antiviral inactivated vaccine after one injection. The efficiency of the new formulation (BioMed) was evaluated with an inactivated porcine strain of influenza (A/Sw/IN/1726/88 H1N1) in the pig model. The first assessment criteria was the follow-up of selected immunological parameters such as, antibody levels, lymphoproliferation, double positive CD4⁺CD8⁺ T lymphocytes and cytokine production (IL-2, IL-4, IFN-. The second criteria was the estimate of the protection level of animals exposed to a homologous challenge of 50 PID₅₀ one month after a single immunizing or control injection. In the BioMed group of animals, 4 pigs (out of 6) were free of macroscopic lesion, while lesions could be seen in all individuals of other groups and virus was isolated in only one animal, whereas all other animals of other groups had virus in their lungs. This better protection of BioMed animals seems to be correlated mainly with higher levels of antibodies and to a lesser extent with a slightly better CMI response and probably with the production of memory CD4⁺CD8⁺ T cells.

Key words: H1N1 swine influenza virus / immunopotentiating adjuvant / inactivated vaccines

Corresponding author: sylvette.laurent-lewandowski@umontreal.ca

© INRA, EDP Sciences 2007