Immunological profile of mice immunized with a polyvalent virosome-based influenza vaccine

Abstract Influenza-based virosome is an effective immunomodulating carrier that replicates the natural antigen presentation pathway and has tolerability profile due to their purity and biocompatibility. Based on that, this study aimed to develop a polyvalent virosome influenza vaccine containing the hemagglutinin and neuraminidase proteins derived from the swine influenza A viruses (IAVs) H1N1, H1N2 and H3N2 viruses, and to investigate its effectiveness in mice as a potential vaccine for swine. The humoral and cellular immune responses in mice vaccinated intranasally or intramuscularly with polyvalent influenza virosomal vaccine were investigated. Only intramuscular vaccination induced high hemagglutination inhibition (HI) titers. Seroconversion and seroprotection (> 4-fold rise in HI antibody titers, reaching a titer of ≥ 1:40) were achieved in 80% of mice (intramuscularly vaccinated group) at 21 days after booster immunization. Long-lasting immunity was observed 8 months after vaccination. Overall, mice immunized with the virosome displayed greater ability for B, effector-T and memory-T cells from the spleen to respond to H1N1, H1N2 and H3N2 antigens. All findings showed an efficient immune response against IAVs in mice vaccinated with a polyvalent virosome-based influenza vaccine.