- Group "ID-JI-0.1" (n = 16) - reduced 0.1 mL INF doses administered intradermally (ID) by needle-free jet injector (JI) (Biojector® 2000 subcutaneous syringe no. 2 [green color code], with 2 cm investigational spacer, Bioject Medical Technologies, Inc., Portland, OR, USA)