Groups of mice (N=11) were intramuscularly vaccinated with 2 × 107, 1 × 108, or 5 × 108 plaque forming units (pfu) of HAd-HA-NP with or without 1 × 107 pfu of HAd-Mbd2. Animals that similarly received 1 × 108 pfu of the HAd-ΔE1E3 or 1 × 108 pfu of HAd-ΔE1E3 + 1 × 107 pfu of HAd-Mbd2 served as controls. At Days 7 or 14 post-immunization, six animals/group were euthanized, and the spleens were collected. Half million splenocytes from immunized mice were cultured in the presence of the HA-518 or NP-147 peptides on an anti-IFN-γ antibody-coated 96-well filter plates and developed according to an ELISpot protocol. The ELISpot plates were read using a Bioreader 5000 (BIOSYS, Miami, FL). The data represent mean ± standard deviation (SD) from six animals per group. *, P≤0.05 compared to mice vaccinated with a similar dose of HAd-HA-NP.