We next explored the effect of BVCARHAdV5-PUMA injection into the synovial cavity of rats with adjuvant-induced arthritis (AIA). This is an animal model of oligo-articular arthritis in which the ankles are particularly affected, with the development of arthritis 8–10 days after adjuvant injection. Rats were given different vector preparations for a single intra-articular injection at day 14 post induction, i.e., at the active stage of the disease, as would be the case in a clinical setting. Thirty rats were divided into six groups (three control and three therapeutic) of five rats each. Rats of control groups were injected with (i) BVCAR alone (105 plaque forming unit (PFU) per joint), (ii) BVCARHAdV5-null (105 PFU BVCAR + 109 PFU HAdV5-null per joint) and (iii) HAdV5-PUMA alone (109 PFU per joint). Rats of the three therapeutic groups were administered BVCAR (105 PFU per joint) complexed with HAdV5-PUMA at three different doses (107, 108 and 109 PFU per joint, respectively) and monitored for 4 days.