Increasing the rate or volume in portal vein injection has no effect on escape of AAV2-hFIX from neutralization. SCID mice (n = 5 per group) were reconstituted with IVIG, resulting in AAV2 neutralizing titers between 1:3.3 and 1:10, followed by portal vein injection of 1 × 10¹¹ vg/mouse of AAV2-hFIX. The rate and volume of delivery are as indicated for each group. Results presented here are mean FIX levels at 4 weeks after vector delivery in each group. Error bars indicate SD.