Cellular immune responses will be assessed before 1st vaccination (day 0), two weeks after 2nd vaccination (day 104 ±2), and one year after the 1st vaccination (day 365) Safety assessments will be made by the investigator at baseline (days -10 to -2, before the 1st immunization) and at day 1, 2, 3, 7, 14, 30 after each vaccination.