AUTHOR=Babb Rachelle , Chan Jennifer , Khairat Jasmine E. , Furuya Yoichi , Alsharifi Mohammed TITLE=Gamma-Irradiated Influenza A Virus Provides Adjuvant Activity to a Co-Administered Poorly Immunogenic SFV Vaccine in Mice JOURNAL=Frontiers in Immunology VOLUME=5 YEAR=2014 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2014.00267 DOI=10.3389/fimmu.2014.00267 ISSN=1664-3224 ABSTRACT=

Many currently available inactivated vaccines require “adjuvants” to maximize the protective immune responses generated against the antigens of interest. Recent studies in mice with gamma-irradiated influenza A virus (γ-FLU) have shown its superior efficacy compared to other forms of inactivated FLU vaccines and its ability to induce both potent interferon type-I (IFN-I) responses and the IFN-I-associated partial lymphocyte activation. Commonly, IFN-I responses induced by adjuvants, combined in vaccine preparations, have been shown to effectively enhance the immunogenicity of the antigens of interest. Therefore, we investigated the potential adjuvant activity of γ-FLU and the possible effect on antibody responses against co-administrated antigens, using gamma-irradiated Semliki Forest virus (γ-SFV) as the experimental vaccine in mice. Our data show that co-vaccination with γ-FLU and γ-SFV resulted in enhanced SFV-specific antibody responses in terms of increased titers by sixfold and greater neutralization efficacy, when compared to vaccination with γ-SFV alone. This study provides promising evidence related to the possible use of γ-FLU as an adjuvant to poorly immunogenic vaccines without compromising the vaccine efficacy of γ-FLU.