Schema of the immunization protocol. Arrows indicate immunizations and circles show serum collections. Thirty-two GPs were divided into eight groups of four animals. The first three groups (12 GPs) received DNA prime followed by protein boost and the second three groups received rAd prime, protein boost. The DNA groups received three i.m. inoculations of 500 ug of plasmid DNA and two 50 ug protein boosts. Protein was formulated with MF59, or with MF59 plus one of two GpG ODN as shown. The rAd groups each received one i.m. inoculation of 1010 PU of rAd and were boosted twice with 50 ug of protein. Protein was again formulated with MF59, or with MF59 plus the ODN. The protein only group received 50 ug i.m. protein formulated with MF59 at weeks 0, 3, 19 and 30. Control group GPs were immunized with an empty rAd vector at week 0 and were boosted with PBS/MF59 at weeks 19 and 30.