Immunization schedule for administration of Lmdd or Lmdd-HIV- gag. A total of 5 individual monkeys were enrolled into 2 immunization groups: Group 1 (animals RMh-8, RSg-8, and RUg-8), received three oral inoculations of Lmdd empty vector alone during experimental phase I; the doses were 1 × 1012 organisms at week 0 followed by 3 × 1012 organisms at weeks 6 and 19 (vaccination shown as vertical arrows) (A). Group 2 (animals RAm-9 and RHm-9) were enrolled. In experimental phase II, both groups received Lmdd-HIV-gag orally in phosphate-buffered saline (PBS) at wks 0, 6, and 19 at 3 × 1012 organisms given for 3 consecutive days (q.d. x 3) depicted in (B). *The dosage (in colony forming units/ml, CFU) administered at each time point is shown in parentheses for each group. All Lmdd-gag vaccinations were preceded by oral administration of saturated sodium bicarbonate. D-ala (640 mg/kg) was co-administered intravenously before and after each vaccine dose . Lmdd inocula were also supplemented with D-ala (0.5 mg/ml in 20 ml) to ensure efficient bacterial replication.