A De-O-acylated Lipooligosaccharide-Based Adjuvant System Promotes Antibody and Th1-Type Immune Responses to H1N1 Pandemic Influenza Vaccine in Mice

Figure 6

Persistence of protective immunity induced by CIA06-adjuvanted Greenflu-S. Mice () were immunized twice with Greenflu-S (0.2 μg) alone or in combination with adjuvants. Various ratios of dLOS and alum were used for comparison. CIA06-1 contains 0.25 μg dLOS and 12.5 μg alum, CIA06-2 contains 0.5 μg dLOS and 12.5 μg alum, and CIA06-3 contains 0.5 μg dLOS and 6.25 μg alum. Mice receiving CIA06-2 or Greenflu-S adjuvanted with AddaVax (50 μL) were included as control groups. Sera were obtained 4 and 24 weeks after immunization, and influenza virus-specific IgG antibody titers (a) and HI antibody titers (b) were determined. (c) Mice were challenged with influenza virus 26 weeks after immunization and monitored for mortality and morbidity for 15 days. Body weight changes of mice relative to their initial body weight were calculated for each group at day 5 after infection, when body weight loss was greatest. Statistical differences were analyzed by one-way ANOVA followed by Tukey’s multiple comparison test. Results are presented as the GMT ± SD of titers ((a) and (b)) or the means ± SD of values (c) that were obtained from six mice in each group. and . NS, not significant.

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