FIG 3.

Impact of the MVA-E1 boost vaccination on the number of recalled HPV16 E1-specific IFN-γ-producing cells (peptide IAYKYAQL) by ex vivo ELISpot assay. Following initial injection schedules, mice from all groups were boosted with MVA-E1 at either day 46, 73, or 129, as indicated by the arrows. Immune responses were monitored 7 days after boost, at days 54, 80, and 136, respectively. The boost at day 129 was also monitored at day 158. The y axis shows the total number of IFN-γ-secreting cells per spleen. Time of sampling is indicated on the x axis. The mean values ± the SEM from two to three independent experiments are represented. In each experiment, five mice were sacrificed and their splenocytes were pooled at each time point. Individual values were calculated as the means of triplicate wells. (A, B, C) One (day 14), two (days 7 and 14), or three (days 0, 7, and 14) immunizations with MVA-E1, respectively. (D) Three immunizations with mock MVA vector (days 0, 7, and 14). Significance was evaluated by Kruskal-Wallis test and Dunn's multiple comparison test for each time point between groups receiving one, two, or three immunizations with MVA-E1. ns, not significant.