Evaluated the cross-protection by intranasal administration of Vero cell-derived attenuated influenza vaccines with compound adjuvant

Objective: This study was to evaluate the sufficient safety and effect of the novel influenza vaccine program, using Vero cell derived live attenuated influenza vaccine (LAIV) with compound adjuvant, through intranasal administration; Methods: : It prepared new reassortant Vero cell adaption virus, and taken high yield. According to the plaque counting, one dose LAIV was composed with 10 PFU of H1, H3, BY and BV, respectively, in 0.1 mL volume. Then mixed this LAIV with compound adjuvant, containing 500 μg/mL of carbopol971P and 50 μg/mL of tetanus toxin. That vaccination was called catt-flu. And it employed the GYZZ02 vaccine (commercialized freeze-dried LAIV, listed in China) as cohort analysis control. The total of two immunizations, by immunize once every two weeks, it used the neutralization test, neuraminidase inhibition, hemagglutination inhibition and animal challenge-testing to detect the cross-protection of catt-ful by intranasal administration. Pathological observation and weight monitoring methods were used to detect its safety; Results: : That catt-flu program could induce more cross-protection with neutralizing antibody against heterogeneous types of influenza virus, not only based on HA but also NA protective antigen, through convenient nasal immunization, which had non-inferiority titter compared with the chicken embryo-derived GYZZ02 vaccine on safe and effect; Conclusion: The Vero cell-derived vaccine (LAIV) combined compound catt adjuvant (contain carbopol971P and tetanus toxin), could provide another safety and protective program of influenza vaccine by intranasal administration, as catt-flu program.