[Evaluation of alum-adjuvanted whole virus influenza vaccine and future aspects of influenza A (H1N1) 2009 vaccine]

Evaluation of immune response following one dose of an AS03A-adjuvanted H1N1 2009 pandemic influenza vaccine in Japanese adults 65 years of age or older

Objective: This study assessed the immunogenicity, long-term persistence of immune response and safety of a single dose of an A/California/07/2009 H1N1 pandemic influenza vaccine adjuvanted with AS03 (α-tocopherol and squalene based oil-in-water emulsion Adjuvant System) in subjects ≥ 65 y of age (NCT01114620).

Results: At Day 21, the HI immune response met all three European guidance criteria [seroconversion rate (SCR): 60.0%; seroprotection rate (SPR): 64.0%; geometric mean fold rise (GMFR): 10.2] and the US guidance criterion for SCR. At month 6, the HI immune response against the A/California/07/2009 H1N1 strain persisted but at levels lower than that observed at Day 21 (SCR: 38.8%; SPR: 42.9%; HI antibody geometric mean titer: 27.6); the European regulatory guidance criteria for SCR and GMFR were still met. Overall, the vaccine was well-tolerated.

Conclusion

A single dose of the 3.75µg HA AS03-adjuvanted H1N1 2009 pandemic vaccine induced immune responses against the vaccine strain that met the European regulatory guidance criteria at day 21 in the elderly Japanese population; the immune response persisted at lower levels at month 6. No safety concerns were identified. These results suggest that two vaccine doses might be useful for the elderly population to improve antibody induction and persistence.

Methods: In this open-label, single group study, 50 subjects received one dose of the 3.75 µg hemagglutinin (HA) AS03-adjuvanted H1N1 2009 vaccine. Immunogenicity assessments were made before vaccination, 21 days and six months after vaccination using hemagglutination inhibition (HI) and microneutralization assays. Immunogenicity end points were based on US and European regulatory criteria.

Capture of influenza viruses and prevention of their infection by coral mineral powder (sango mineral powder)

The anti-influenza virus activity of fossilized marine coral powder (sango mineral powder, SMP) was studied. SMP is composed in terms of mass of around 25 % of calcium and 10 % of magnesium, respectively, principally as dolomite (CaMg(CO(3))(2)) but not as calcium oxide (CaO) or magnesium oxide (MgO). By mixing the influenza virus with SMP, the infectivity of the virus substantially decreased and there was more than a 10(4) reduction on the 3rd d of infection. The antiviral effect was observed against all the type A and B strains of the influenza virus examined including the H1N1 2009 pandemic and H5N1 avian viruses. The surface structure of SMP was highly porous and the anti-influenza activity was explained by the adsorption of the viral particles onto its surface. The binding of viruses to SMP was strong and stable in the physiological condition, and the attached viruses detached only in the presence of a high concentration of phosphate. This was similar to the binding of protein to hydroxyapatite, suggesting an ionic interaction between SMP and the viral proteins. SMP maintained its activity to capture influenza viruses even after being immobilized on a non-woven textile. SMP would be useful as a practical anti-influenza tool especially in preparation for the next pandemic virus.