Matrix-M™ adjuvation broadens protection induced by seasonal trivalent virosomal influenza vaccine.

Freek Cox,Jeroen Tolboom,Wouter Koudstaal,Eirikur Saeland,Matthijs Baart,Jaap Goudsmit,Martin Koldijk,Katarina Radošević,Liesbeth Dekking,Karin Lövgren Bengtsson

doi:10.1186/s12985-015-0435-9

Abstract

BackgroundInfluenza virus infections are responsible for significant morbidity worldwide and therefore it remains a high priority to develop more broadly protective vaccines. Adjuvation of current seasonal influenza vaccines has the potential to achieve this goal.MethodsTo assess the immune potentiating properties of Matrix-M™, mice were immunized with virosomal trivalent seasonal vaccine adjuvated with Matrix-M™. Serum samples were isolated to determine the hemagglutination inhibiting (HAI) antibody titers against vaccine homologous and heterologous strains. Furthermore, we assess whether adjuvation with Matrix-M™ broadens the protective efficacy of the virosomal trivalent seasonal vaccine against vaccine homologous and heterologous influenza viruses.ResultsMatrix-M™ adjuvation enhanced HAI antibody titers and protection against vaccine homologous strains. Interestingly, Matrix-M™ adjuvation also resulted in HAI antibody titers against heterologous influenza B strains, but not against the tested influenza A strains. Even though the protection against heterologous influenza A was induced by the adjuvated vaccine, in the absence of HAI titers the protection was accompanied by severe clinical scores and body weight loss. In contrast, in the presence of heterologous HAI titers full protection against the heterologous influenza B strain without any disease symptoms was obtained.ConclusionThe results of this study emphasize the promising potential of a Matrix-M™-adjuvated seasonal trivalent virosomal influenza vaccine. Adjuvation of trivalent virosomal vaccine does not only enhance homologous protection, but in addition induces protection against heterologous strains and thus provides overall more potent and broad protective immunity.Electronic supplementary materialThe online version of this article (doi:10.1186/s12985-015-0435-9) contains supplementary material, which is available to authorized users.

Highlights

Influenza virus infections are responsible for significant morbidity worldwide and it remains a high priority to develop more broadly protective vaccines
Matrix-MTM-adjuvated trivalent virosomal vaccine (TVV) elicits high homologous hemagglutination inhibiting (HAI) and protection To investigate whether Matrix-MTM can enhance the overall humoral immune responses after immunization with TVV, we first evaluated vaccine homologous HAI responses in mice against all three vaccine strains: H1N1, H3N2 and B
A single immunization with a trivalent virosomal vaccine (TVV) alone did not result in HAI responses against the vaccine homologous H1N1 A/California/07/09

Summary

Introduction

Influenza virus infections are responsible for significant morbidity worldwide and it remains a high priority to develop more broadly protective vaccines. Influenza virus infections cause significant morbidity and mortality, with 5 million severely ill and 250 –500.000 deaths annually, in particular among the elderly, the immunocompromised and people with chronic diseases. The estimated global attack rate of influenza virus is 5 – 10 % for adults and 20 – 30 % for children, which causes large health and economic burdens for the society [1]. Circulating seasonal influenza strains belong to A and B viruses. There is a constant threat of influenza A viruses crossing the species barrier and causing serious disease burden in humans [6], as was recently demonstrated by human cases of avian H7N9 in China [7]

Methods

Results

Discussion

Conclusion