Determination of the optimal dosage of MVA-Gag<sup>M</sup> to boost a BCG-Gag<sup>M</sup> prime.

<p>(<b>A)</b> Mice were primed on day 0 with 2 x 10<sup>7</sup> cfu BCG-Gag<sup>M</sup> (Group 1–3) or BCG<sup>E</sup> (Group 4–6) and boosted on day 70 with 10<sup>2</sup> (Group 1 and 4), 10<sup>4</sup> (Group 2 and 5), or 10<sup>6</sup> (Group 3 and 6) pfu MVA-Gag<sup>M</sup>. (<b>B</b>) Cumulative IFN-γ ELISPOT CD8<sup>+</sup> and CD4<sup>+</sup> responses of vaccinated mice to HIV-1 Gag peptides. The ELISPOT assay was carried out using three Gag-specific peptides for stimulation of pooled splenocytes that were isolated 12 days post the MVA-Gag<sup>M</sup> boost. Bars represent the magnitude of net responses to individual peptides, expressed as sfu/10<sup>6</sup> splenocytes after subtracting the background. (<b>C</b>) and (<b>D</b>) Total frequency of T cells producing IFN-γ, IL-2, and/or TNF-α, after subtracting the background, in response to HIV-1 Gag peptide stimulation following a rBCG prime and an MVA-Gag<sup>M</sup> boost at different doses. Cells were positive for cytokine production if the proportion was ≥0.05% after subtracting the background. These results are from a single experiment using pooled splenocytes.</p>