Fig. 4: Ad26.RSV.preF induces long lived cellular responses in neonatal mice.

Pups were subcutaneously immunized at Day 4 or 5 after birth, and boosted 3 or 6 weeks later with 10¹⁰ vp Ad26.RSV.preF in the immunization regimens displayed. Control groups received no immunization (indicated with -), or FI-RSV. Splenocytes were isolated 9 weeks (n = 6 per group, panels a and c), or 25 weeks (n = 6 per group, panel b) after prime immunization, and stimulated overnight with a peptide pool representing the F protein from RSV A2. a and b IFN-γ ELISPOT results were expressed as spot forming units/10⁶ splenocytes. The background level (95th percentile of unstimulated splenocytes) is indicated with a dotted line. c The percentages of CD3⁺CD8⁺ cells (upper panels) or CD3⁺CD4⁺ (lower panels) producing IFN-γ, IL-2, and TNF-α were determined by intracellular cytokine staining. The black bars specify the geometric mean response within each group. Statistical analysis was performed with Wilcoxon Rank Sum test and Bonferroni correction, or Tobit regression and Tukey or Tukey–Kramer correction.